This adds the implementation of the commitlog API.
Current implementation contains:
/commitlog/segments/active
That returns a list of the active file names, and
/commitlog/segments/archiving
Which always return an empty list as we archiving is not supported at
the moment
The doc file is under:
/api-doc/commitlog
Signed-off-by: Amnon Heiman <amnon@cloudius-systems.com>