esp-face: master 420fc7e
esp32-camera: master 0107093

Follow up for https://github.com/espressif/arduino-esp32/pull/4564

Added guarded define to set the stacksize on the main looptask.
Advantage of this is that build_flags can be used to provide a different value for the stack size should it be neccessary
default behaviour is unaffected

Replace (depricated) bzero, bcopy with memset and memcpy.

Replace (depricated) bzero with memset.

esp-face: master 420fc7e
esp32-camera: master 0107093

Fixes #4558

Set the category to silence this warning in the Arduino IDE:
```
WARNING: Category '' in library WiFiProv is not valid. Setting to 'Uncategorized'
```

The goal is to allow custom configuration for `variants_dir` to define our own board variant directly in the project.

With this functionnality, we are now allowed to define in our projects a custom board **AND** a custom variant.
https://docs.platformio.org/en/latest/platforms/creating_board.html#custom-embedded-boards

Here is an example of how to define a custom board with custom variant:
```
my_project
├── boards
│   └── custom_esp32dev.json
└── variants
    └── custom-esp32dev
        └── pins_arduino.h
```

custom_esp32dev.json
```json
{
  "build": {
    "arduino":{
      "ldscript": "esp32_out.ld"
    },
    "core": "esp32",
    "extra_flags": "-DARDUINO_ESP32_DEV",
    "f_cpu": "240000000L",
    "f_flash": "40000000L",
    "flash_mode": "dio",
    "mcu": "esp32",
    "variants_dir": "variants",
    "variant": "custom-esp32dev"
  },
  "connectivity": [
    "wifi",
    "bluetooth",
    "ethernet",
    "can"
  ],
  "debug": {
    "openocd_board": "esp-wroom-32.cfg"
  },
  "frameworks": [
    "arduino",
    "espidf"
  ],
  "name": "My Custom Espressif ESP32 Dev Module",
  "upload": {
    "flash_size": "4MB",
    "maximum_ram_size": 327680,
    "maximum_size": 4194304,
    "require_upload_port": true,
    "speed": 460800
  },
  "url": "https://en.wikipedia.org/wiki/ESP32",
  "vendor": "Espressif"
}
```

https://github.com/espressif/arduino-esp32/issues/3652

Do not pollute the global namespace with generic names like 'config' by declaring global variables 'static'.

Fixes https://github.com/espressif/arduino-esp32/issues/4466

pgmspace.h missing 'pgm_get_far_address'

See #3960 for more details of the problem and the solution. I only implemented what was proposed in this ticket, as it solves my problem, which was the same as in this ticket. Credits for the code going to @etrinh ;-)

This also is a more consistence behaviour compared to esp8266, where it also is possible to restart the wifiserver immediately on the same port.