* General tests like page loading from flash
* Rough test of fixed-size data types
* Rough test of blob read
* Added coverage target in cmake, also accessible
via `idf.py coverage`
* Fixed unsigned comparison in comp. enum table
* introducing temporary LINUX_TARGET define
* partition api changed from spi_flash* API to
esp_partition* API and is abstracted as a C++
interface.
* The old nvs encryption is still possible
* changed default unit test app partition table
* Partitions coming from esp_partition API are
checked for generic flash encryption. If yes,
an error is returned since generic flash
encryption isn't compatible with nvs
encryption
* esp32, esp32s2 tests don't require nvs_flash
but mbedtls now
Closes IDF-1340
Closes IDF-858
* Philosophical: "explicit is better than implicit".
* Practical: Allows useful errors if invalid directories given in components as the defaults aren't
always used. Also trims the -I path from a number of components that have no actual include
directory.
* Simplifies knowing which components will be header-only and which won't
