Merge branch 'feature/wdts' into 'master'

Feature/wdts

This adds two watchdogs to  esp-idf:

- An interrupt watchdog. Kicks in if the FreeRTOS timer interupt on either the PRO_CPU or (when configured) the APP CPU isn't called for a configurable time. Panics, displaying which CPU caused the problem and the registers that may lead to the offending code.
- A task watchdog. A task has to feed it every once in a while. If not, it will print the name of the offending tasks, as well as the tasks currently running on both CPUs, and optionally panic.

Also adds a panic reason to the panic call, as well as fixes the panic code a bit.

See merge request !148

diff --cc components/freertos/include/freertos/FreeRTOSConfig.h
Simple merge

diff --cc components/freertos/include/freertos/task.h
Simple merge

diff --cc components/freertos/tasks.c
Simple merge

diff --cc components/freertos/xtensa_vectors.S
Simple merge