Redmine#6179: document if and unless promise attributes
Merge pull request #847 from tzz/doc/redmine6179-if-unless

Redmine#6179: document if and unless promise attributes
Removed a mention of MongoDB
Merge pull request #848 from KevWright/master

Removed a mention of MongoDB
Unpublished Enterprise API doc in reference - outdated
Merge pull request #849 from KevWright/master

Unpublished Enterprise API doc in reference - outdated
Republished doc due to error
Commented out outdated content in enterprise API doc - it is now empty.
Merge pull request #850 from KevWright/master

Fixed problem with enterprise api doc