[rrl] Add unittests for getFullHash()
[rrl] Add API doc for RRLKey class
[rrl] Simplify comparison
[rrl] Indent code
[rrl] Add API doc for RRLTimeStampBases
[rrl] Remove a (very) confusing comment

It's simpler to just read the deltaTime() description.
[rrl] Use doxygen syntax
[rrl] Add comment about why bases_ is not a simple array
[rrl] Update unittest comments