Fixes and cleanups to hgeditor:
- "HG: merge resolve" isn't supported for a long time now.
- detection of unchanged commit message if signing is turned off.
- don't add manifest hash to commit message if not signing.
+ hg init+ echo This is file a1+ hg add a+ hg commit -m 'commit #0' -d '0 0'+ lsa+ echo This is file b1+ hg add b+ hg commit -m 'commit #1' -d '0 0'+ hg co 0+ lsa