using phases to count outgoing revisions in mercurial repos

Closed Johann Dreo requested to merge github/fork/hcgraf/develop into develop

Created by: hcgraf

This change counts the commits in the "draft" phase and shows that as the number of outgoing commits. It's much cheaper than actually contacting the remote. For very old versions of Mercurial (not supporting phases) it will always result in zero (same as before this change)

I also removed the corresponding line in "Known Limitations".

To read on Phases, see

Merge request reports