thans @martinayotte

* Support self signed certificates

Fix for https://github.com/espressif/arduino-esp32/issues/265

mbedtls_ssl_conf_authmode was defined before mbedtls_ssl_config_defaults causing several bugs when no CA certificate is defined.

* Implement Arduino's log facility

Replace printf by ESP log handling

* Remove \n from debug messages

log_ doesn't need \n to break line.

Should Fix: https://github.com/espressif/arduino-esp32/issues/234

Thanks @marcmerlin and @MartyMacGyver

Fixes: https://github.com/espressif/arduino-esp32/issues/275

Fixes: https://github.com/espressif/arduino-esp32/issues/263

Fixes: https://github.com/espressif/arduino-esp32/issues/270

Actually WiFiMulti is not working due some functions haven't equal comportment of ESP8266
Replace status == WL_DISCONNECTED => status != WL_CONNECTED
Replace scanComplete() => scanNetworks()

Maybe is more interesting, for keep the maximum compatibility, investigate why WL_DISCONNECTED and scanComplete() doesn't works in this case instead of just replace by this pull request.

Closes: https://github.com/espressif/arduino-esp32/pull/267

The card seems to need a bit of a nudge at boot to properly mount
sometimes.
Fixes: https://github.com/espressif/arduino-esp32/issues/272

Some boards have different default pins for SPI

Thanks @Ladyada

It's look more a practical guide "how to use SD lib"

* Add Sketch Update Library

* Add MDNS Library

* Add Arduino OTA Library

* add missing library file

* Add library files for Update

* Add missing headers

* fix ota command

* Add espota binary

* remove bad example

* PlatformIO does not auto forward declare methods like Arduino Builder

* Add CA certificate in example

SHA1 fingerprint is broken now: more info: https://shattered.io

* Best error handling

When occur an error in WiFiClientSecure library just return the error message
and clean the context avoiding crash - fix for https://github.com/espressif/arduino-esp32/issues/211

Translate MbedTLS error codes in messages for best understanding

* Declarate certificates as const

mbedtls_pk_parse_key needs a const unsigned char * certificate. In old implementation the certificate was declarated as char * so first it converts to unsigned and after to const.

When we convert signed to unsigned it may result in a +1 larger output.

Fix issue https://github.com/espressif/arduino-esp32/issues/223

* add DFRobot FireBeetle-ESP32 support

* add variant for fireBeetle-ESP32

* The name of the env variant is changed to firebeetle32

connected to: https://github.com/espressif/arduino-esp32/issues/220 and
https://github.com/espressif/arduino-esp32/issues/161

fixes: https://github.com/espressif/arduino-esp32/issues/119

thanks @Curclamas for pointing it out :)

* Rework WiFiClient

Rework WiFiClient to correct error where making a copy of a WiFiClient object resulted in the socket being closed prematurely.

Added loop and select to write to handle/prevent EAGAIN errors.

* Rework WiFiClient to use shared_ptr

Rework changes to utilize shared_ptr rather than manually maintaining reference count. 

Revert changes to write

* Incorporate comments from review

Move WiFiClientSocketHandle and fd() into WiFiClient.cpp

The send call may return EAGAIN. This indicates a recoverable error and a retry should be attempted. The current implementation treats this as a fatal error. Further, the current implementation strips the error code, setting it to 0, which prevents the caller from handling it directly. 
This change utilizes select to verify the socket is available prior to calling send and will retry on an EAGAIN condition.