With the new ETS task handling thread, the stack sizes could be down sized.

Changes of ETS task handling require the context switch by software interrupt. The context switch based on interrupt is therefore enabled by default. Furthermore, the number of priority levels are increased due to the new additional thread.

ETS tasks are now handled by a high priority RIOT thread

boards/b-l475e-iot01a: provide already configured RTC and RTT features

RTC and RTT are available and already configured for this board but not provided by the build system

cpu/esp32: fixes the memset optimization problem in esp_wifi/wpa_supplicant

nrfmin: fix type for NETOPT_PROTO

Makefile.include: append the values to GLOBAL_GOALS

The type [is documented as `gnrc_nettype_t`][1] so it should by checked
as such.

[1]: https://github.com/RIOT-OS/RIOT/blob/f9a3bdf1a749f0e6a0d9e79eee652d8b31d4d9e0/sys/include/net/netopt.h#L210-L212

net/nanocoap: fix confirmable retry countdown

eui48: fix type alignment

This allows setting other GLOBAL_GOALS by setting it before.
This could be the case for the application `Makefile` or files parsed
from `RIOT_MAKEFILES_GLOBAL_PRE`.

tests/pkg_{hacl,monocypher}: set custom timeout value

tests/periph_rtc: add automatic python test script

tests/periph_flashpage: improve flashpage tests

On samr30-xpro the tests takes respectively 20 and 14 seconds to complete

examples/gcoap: verify buffer size

tests/periph_rtc: fix alarm period in README

The default period value the application code is set to 2s

doc: fix warnings in *_params.h

nrfmin: remove long address support

pkg/nordic_softdevice_ble: Use MAC48 as hardware address

This is just a compatibility issue waiting to happen as soon as there
is support for a more standard-compliant implementation of BLE (like
e.g. NimBLE ;-)).

boards/hifive1: fix file permissions of flasher.sh

cpu/esp32: esp_wifi netdev driver

ESP-IDF heap handling has to be used for esp_wifi for stability reasons. Otherwise, heap is corrupted sporadically

Fixes sporadic blocking of the wifi thread in esp_wifi_recv_cb function under heavy network load conditions when frames are coming in faster than they can be processed. Since esp_wifi_recv_cb function is not executed in interrupt context, the msg_send function used for ISR event can block when the message queue is full. With this change esp_wifi can be flooded with icmpv6 packets of maximum size without any problems over hours.

To avoid further inconsistencies in documentation, README.md is not provided any longer