devel/got: update to 0.92

User-visible changes:
- allow modified files to be deleted during merges if content exists in repo
- disallow overlapping repo and work tree in 'got checkout'
- add support for commit keywords to 'got log -x'
- fix 'got log -dPp' diffstat duplication bug
- fix regression from 0.76: 'got diff' output matches /usr/bin/diff -p again
- tog: show work tree base commit marker in the log view