🏗 Merge C++ into python codebase (#504)

## Description:

Move esphome-core codebase into esphome (and a bunch of other refactors). See https://github.com/esphome/feature-requests/issues/97

Yes this is a shit ton of work and no there's no way to automate it :( But it will be worth it 👍

Progress:
- Core support (file copy etc): 80%
- Base Abstractions (light, switch): ~50%
- Integrations: ~10%
- Working? Yes, (but only with ported components).

Other refactors:
- Moves all codegen related stuff into a single class: `esphome.codegen` (imported as `cg`)
- Rework coroutine syntax
- Move from `component/platform.py` to `domain/component.py` structure as with HA
- Move all defaults out of C++ and into config validation.
- Remove `make_...` helpers from Application class. Reason: Merge conflicts with every single new integration.
- Pointer Variables are stored globally instead of locally in setup(). Reason: stack size limit.

Future work:
- Rework const.py - Move all `CONF_...` into a conf class (usage `conf.UPDATE_INTERVAL` vs `CONF_UPDATE_INTERVAL`). Reason: Less convoluted import block
- Enable loading from `custom_components` folder.

**Related issue (if applicable):** https://github.com/esphome/feature-requests/issues/97

**Pull request in [esphome-docs](https://github.com/esphome/esphome-docs) with documentation (if applicable):** esphome/esphome-docs#<esphome-docs PR number goes here>

## Checklist:
  - [ ] The code change is tested and works locally.
  - [ ] Tests have been added to verify that the new code works (under `tests/` folder).

If user exposed functionality or configuration variables are added/changed:
  - [ ] Documentation added/updated in [esphomedocs](https://github.com/OttoWinter/esphomedocs).

esphome/components/deep_sleep/__init__.py

@@ -0,0 +1,106 @@
+from esphome import pins
+import esphome.config_validation as cv
+import esphome.codegen as cg
+from esphome.automation import ACTION_REGISTRY, maybe_simple_id
+from esphome.const import CONF_ID, CONF_MODE, CONF_NUMBER, CONF_PINS, CONF_RUN_CYCLES, \
+    CONF_RUN_DURATION, CONF_SLEEP_DURATION, CONF_WAKEUP_PIN
+
+
+def validate_pin_number(value):
+    valid_pins = [0, 2, 4, 12, 13, 14, 15, 25, 26, 27, 32, 39]
+    if value[CONF_NUMBER] not in valid_pins:
+        raise cv.Invalid(u"Only pins {} support wakeup"
+                         u"".format(', '.join(str(x) for x in valid_pins)))
+    return value
+
+
+deep_sleep_ns = cg.esphome_ns.namespace('deep_sleep')
+DeepSleepComponent = deep_sleep_ns.class_('DeepSleepComponent', cg.Component)
+EnterDeepSleepAction = deep_sleep_ns.class_('EnterDeepSleepAction', cg.Action)
+PreventDeepSleepAction = deep_sleep_ns.class_('PreventDeepSleepAction', cg.Action)
+
+WakeupPinMode = deep_sleep_ns.enum('WakeupPinMode')
+WAKEUP_PIN_MODES = {
+    'IGNORE': WakeupPinMode.WAKEUP_PIN_MODE_IGNORE,
+    'KEEP_AWAKE': WakeupPinMode.WAKEUP_PIN_MODE_KEEP_AWAKE,
+    'INVERT_WAKEUP': WakeupPinMode.WAKEUP_PIN_MODE_INVERT_WAKEUP,
+}
+
+esp_sleep_ext1_wakeup_mode_t = cg.global_ns.enum('esp_sleep_ext1_wakeup_mode_t')
+Ext1Wakeup = deep_sleep_ns.struct('Ext1Wakeup')
+EXT1_WAKEUP_MODES = {
+    'ALL_LOW': esp_sleep_ext1_wakeup_mode_t.ESP_EXT1_WAKEUP_ALL_LOW,
+    'ANY_HIGH': esp_sleep_ext1_wakeup_mode_t.ESP_EXT1_WAKEUP_ANY_HIGH,
+}
+
+CONF_WAKEUP_PIN_MODE = 'wakeup_pin_mode'
+CONF_ESP32_EXT1_WAKEUP = 'esp32_ext1_wakeup'
+
+CONFIG_SCHEMA = cv.Schema({
+    cv.GenerateID(): cv.declare_variable_id(DeepSleepComponent),
+    cv.Optional(CONF_RUN_DURATION): cv.positive_time_period_milliseconds,
+
+    cv.Optional(CONF_SLEEP_DURATION): cv.positive_time_period_milliseconds,
+    cv.Optional(CONF_WAKEUP_PIN): cv.All(cv.only_on_esp32, pins.internal_gpio_input_pin_schema,
+                                         validate_pin_number),
+    cv.Optional(CONF_WAKEUP_PIN_MODE): cv.All(cv.only_on_esp32,
+                                              cv.one_of(*WAKEUP_PIN_MODES), upper=True),
+    cv.Optional(CONF_ESP32_EXT1_WAKEUP): cv.All(cv.only_on_esp32, cv.Schema({
+        cv.Required(CONF_PINS): cv.ensure_list(pins.shorthand_input_pin, validate_pin_number),
+        cv.Required(CONF_MODE): cv.one_of(*EXT1_WAKEUP_MODES, upper=True),
+    })),
+
+    cv.Optional(CONF_RUN_CYCLES): cv.invalid("The run_cycles option has been removed in 1.11.0 as "
+                                             "it was essentially the same as a run_duration of 0s."
+                                             "Please use run_duration now.")
+}).extend(cv.COMPONENT_SCHEMA)
+
+
+def to_code(config):
+    var = cg.new_Pvariable(config[CONF_ID])
+    yield cg.register_component(var, config)
+
+    if CONF_SLEEP_DURATION in config:
+        cg.add(var.set_sleep_duration(config[CONF_SLEEP_DURATION]))
+    if CONF_WAKEUP_PIN in config:
+        pin = yield cg.gpio_pin_expression(config[CONF_WAKEUP_PIN])
+        cg.add(var.set_wakeup_pin(pin))
+    if CONF_WAKEUP_PIN_MODE in config:
+        cg.add(var.set_wakeup_pin_mode(WAKEUP_PIN_MODES[config[CONF_WAKEUP_PIN_MODE]]))
+    if CONF_RUN_DURATION in config:
+        cg.add(var.set_run_duration(config[CONF_RUN_DURATION]))
+
+    if CONF_ESP32_EXT1_WAKEUP in config:
+        conf = config[CONF_ESP32_EXT1_WAKEUP]
+        mask = 0
+        for pin in conf[CONF_PINS]:
+            mask |= 1 << pin[CONF_NUMBER]
+        struct = cg.StructInitializer(
+            Ext1Wakeup,
+            ('mask', mask),
+            ('wakeup_mode', EXT1_WAKEUP_MODES[conf[CONF_MODE]])
+        )
+        cg.add(var.set_ext1_wakeup(struct))
+
+    cg.add_define('USE_DEEP_SLEEP')
+
+
+DEEP_SLEEP_ACTION_SCHEMA = maybe_simple_id({
+    cv.Required(CONF_ID): cv.use_variable_id(DeepSleepComponent),
+})
+
+
+@ACTION_REGISTRY.register('deep_sleep.enter', DEEP_SLEEP_ACTION_SCHEMA)
+def deep_sleep_enter_to_code(config, action_id, template_arg, args):
+    var = yield cg.get_variable(config[CONF_ID])
+    type = EnterDeepSleepAction.template(template_arg)
+    rhs = type.new(var)
+    yield cg.Pvariable(action_id, rhs, type=type)
+
+
+@ACTION_REGISTRY.register('deep_sleep.prevent', DEEP_SLEEP_ACTION_SCHEMA)
+def deep_sleep_prevent_to_code(config, action_id, template_arg, args):
+    var = yield cg.get_variable(config[CONF_ID])
+    type = PreventDeepSleepAction.template(template_arg)
+    rhs = type.new(var)
+    yield cg.Pvariable(action_id, rhs, type=type)