statecheck: added support for STATES
This removes STATES from state.py and adds support to
statecheck class to handle its features.
getrepostate() function is modified accordingly.
This adds a method 'cmdutil.addunfinished()' for appending to
the unfinishedstate list so as to keep 'merge' and 'bisect' at the last.
This also makes two separate message formats for checkunfinished() and
getrepostate() as there were previously present.
Results of test changed are shown.
Differential Revision: https://phab.mercurial-scm.org/D6503