context: rename troubled into isunstable As we changed the meaning of unstable between the old vocabulary and the new one, we can't reuse the unstable method name at the risk of breaking extensions calling unstable and getting a wrong result. Instead rename troubled into isunstable so extensions will continue to work. The renaming is done according to https://www.mercurial-scm.org/wiki/CEDVocabulary. Differential Revision: https://phab.mercurial-scm.org/D242

context: rename bumped into phasedivergent Rename bumped context method into phasedivergent and add a deprecation warning on bumped. Only update all callers to keep the patch straightforward. The renaming is done according to https://www.mercurial-scm.org/wiki/CEDVocabulary. Differential Revision: https://phab.mercurial-scm.org/D241