By returning result as a signed 32-bit int between INT32_MIN to IN32_MAX
which is represented the same regardless of 64-bit support or
integral-only builds.
Also updated docs, fixed links and clarified behavior of random APIs
when WiFi isn't started.
Changes have been kept to a minimum, but a serious chunk of work was
needed to move from 8266isms to IDFisms.
Some things got refactored into components/lua/common, in particular
the LFS location awareness.
As part of this work I also evicted our partition table manipulation
code, as with the current IDF it kept breaking checksums and rendering
things unbootable, which is the opposite of helpful (which was the
original intent behind it).
The uart module got relocated from base_nodemcu to the modules component
properly, after I worked out how to force its inclusion using Kconfig alone.
Tom Sutcliffe
Johny Mattsson
Johny Mattsson