* Add Ticker library

* Fix CI (#1)

remove LED_BUILTIN in examples

fix upload.maximum_size as current partition size 0x140000 for esp32vn-iot-uno & heltec boards (#1052)

As discussed in #1042.

* enchanced EEPROMClass

* Added eeprom examles and modified partition

* added eeprom class and extra examples

* No changes

* No changes

* added eeprom class and examples

* fixed typo

* length() returns user-defined sector size

* updated and annotated example

* Retrieve some code from what has been done on the ESP8266. Clarify a bit the signification of several bytes in the response.

* Add the type and class as members of the DNS class for an eventual future use.

* Clarify the sense of a magic number present in DNS server.

* A bit of aesthetics for the DNS server.

* Add a structure for the DNS question, use it DNS server to store the question data and to create the DNS answer from scratch.

* Added a lastError method to WiFiClientSecure so that a connection error from mbedTLS can be retrieved if connection fails (and then presented to a user).

* Changed to dos CRLF

* Made buffer size a const\nMore cleanup to match source

adding an additional step that is required to make sure the BLE libs are synced

See: https://travis-ci.org/felis/USB_Host_Shield_2.0/jobs/328511332 and https://github.com/PaulStoffregen/cores/commit/8a02ea67f577c1798b50c38da9b74296a861b45a#diff-6e1ff9551639ac89d99617863bf84e10

* Small grammar fixes and clarifications

Just fixed some small grammar issues in the comments and clarified a few things that might seem confusing.

* More spelling fixes that I introduced...

This fixes the compile error when we include SPI.h

* Update mDNS and LEDC

* update toolchain

* Update IDF to 1c3dd23

* Advertise the board variant for Arduino OTA

* Add generic variant definition for mDNS

Update to make use of SSL a bit less confusing by ensuring errors are generated if the wrong method is called to retrieve the data stream. (#934)

* Allow configuration of Ethernet PHY clock source
Refer to https://github.com/espressif/esp-idf/pull/1127
The internal APLL can be used to generate the 50MHz clock for the internal EMAC and the external Ethernet PHY.
The clock can either be input on GPIO0 (as before) or output on GPIO0, GPIO16 or GPIO17 (only GPIO17 extensively tested).
New example available.

* Allow configuration of Ethernet PHY clock source
Refer to https://github.com/espressif/esp-idf/pull/1127
The internal APLL can be used to generate the 50MHz clock for the internal EMAC and the external Ethernet PHY.
The clock can either be input on GPIO0 (as before) or output on GPIO0, GPIO16 or GPIO17 (only GPIO17 extensively tested).
New example available.

Make sure to remove that next rebuild

Closes: https://github.com/espressif/arduino-esp32/pull/820

When user selected HSPI with SPIClass name(HSPI) ESP was, by default,
still using VSPI ports (the ones defined in pins_arduino.h).
With this change when user selects HSPI then HSPI default ports will be
used.
If user won't specify HSPI then VSPI default ports will be used.
If user will specify SCLK, MOSI, MISO and SS with SPI.begin() then user
defined ports will be used no matter if VSPI or HSPI is selected.
With this change fe. SD library can use default HSPI ports. It was
possible to
pass HSPI SPI instance to SD lib, however even then it was using VSPI
ports which were (probably) GPIO matrixed to HSPI.