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.

#!/bin/sh -x

hg init
echo a > a
hg add a
hg commit -m "test" -d "0 0"
hg history
hg tag -d "0 0" "bleah" 
hg history

echo foo >> .hgtags
hg tag -d "0 0" "bleah2" || echo "failed"