* Start on documenting features and components
* Missed some renames
* Go through all cellular and 802.15.4 modules
* Fix build
* Fix style
* Update copyright year
ARMCC provides __semihost via compat header. As CMSIS 5.8.0 removed this compat header,
we need to explicitly include it to fix definition missing error.
Also includes:
* rename `mbed_sleep_manager.c` to `mbed_power_mgmt.c` to match its
header file
* create Doxygen groups for public and internal APIs
* use relative path to include header files where inconsistent
* update references to internal APIs throughout libraries
* update the copyright year for all modified files
Jamie Smith
Martin Kojtal
Hugues Kamba