Don't make -C imply -c (a break statement was missing). Detect -an and -cn conflicts. Simplify by removing unneeded check for conflicting -aC (since -C requires -c, we can rely on the -ac conflict being detected). Update the man page to say -cC is allowed.

ok stsp@

ok op, james

When users run 'got add *' the shell may pick up already versioned files and trigger errors about paths being in an unexpected status. Expand the check which previously only allowed files in added status to be double-added to cover the following status codes which are all safe to ignore: A M C m This should make bulk additions of files a bit easier in most cases. Problem reported by robert@ ok jamsek

Split part of got_worktree_merge_prepare into a new function, got_worktree_merge_write_refs, since that part doesn't make sense in the fast-forward case. ok stsp@

Requested by James Cook

problem found by naddy@