Captive portal fixes (#766)

* Enable MDNS logs comment

* Work around ESP8266 mDNS broken for AP

See also https://github.com/esp8266/Arduino/issues/6114

* Enable captive_portal in AP-only mode

Fixes https://github.com/esphome/issues/issues/671

* Make ESP32 connecting faster

See also https://github.com/espressif/arduino-esp32/pull/2989

* Format

esphome/components/logger/__init__.py

@@ -123,6 +123,8 @@ def to_code(config):
             'TLS_MEM',
             'UPDATER',
             'WIFI',
+            # Spams logs too much:
+            # 'MDNS_RESPONDER',
         }
         for comp in DEBUG_COMPONENTS:
             cg.add_build_flag("-DDEBUG_ESP_{}".format(comp))