Commit Briefs
test and fix 'got revert' with a path in a sub-directory
Relax input path requirements of got_object_id_by_path() to make things easier to callers. Allows the revert code to pass a path from the file index in lieu of a repository path.
got_error_from_errno -> got_error_prefix_errno
also add got_error_prefix_errno2 and got_error_prefix_errno3 which should hopefully all be merged into a single function with variadic args (but can't alloc mem)