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@

Previously, this command would trigger an error: got: /: bad path

fixes "proc (null)" appearing in gotd logs

in 1a0c81fb61 I've added a range check too strict for max_repos_display, as zero is allowed and means "show all the repositories".

ok op@

This adds the functions got_repo_cleanup_prepare() and _complete() to lock/unlock the repository to prevent multiple `gotadmin cleanup' or `git gc' operations to run in parallel. improvements and ok stsp@

it's redundant with GOT_ERR_BAD_QUERYSTRING; convert its only use to the latter.

All the special cases are now being explained last.

improvements and ok stsp@

Diff from James Cook, thanks!

noticed since gotwebd fails when there's a ref.lock file due to a concurrent update. discussed with stsp.