* Change Doxygen groups structure, splitting first by Public/Internal
This commit also does the following:
* groups the documentation of related API
* moves `events/internal/equeue.h` to `events/equeue.h`
* merges `events/source/README.md` to `events/README.md`
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
stop using scope for \addtogroup. It was placing class methods into the
group documentation instead of the class documentation. The new style is
to explicitly tag the class as @ingroup. This new method will allow the
class to be linked in the group page, and the class page will contain
the detailed documentation of the class methods.
Hugues Kamba
Martin Kojtal
Senthil Ramakrishnan
Sam Grove
Jimmy Brisson