Add some doc comments and implement new statistics page

Add several doc comments in the API DAOs. Also adds a new page
for displaying site stats. This is ongoing work and simply works
as a first draft. This also modifies the login logging so that openID
logins are being tracked also. Part of #758 and #793
Add doc comments to the API Task DAO

Part of #758
Merge branch 'develop' of github.com:TheRosettaFoundation/SOLAS-Match into develop

Conflicts:
	api/DataAccessObjects/OrganisationDao.class.php
	api/DataAccessObjects/ProjectDao.class.php
	api/DataAccessObjects/TagsDao.class.php
	api/DataAccessObjects/TaskDao.class.php