Sometimes it is desirable to have non-fast-forward branches in a
shared repository. A typical example of that is the 'pu' branch.
This patch extends the format of allowed-users and allow-groups
files by using the '+' sign at the beginning as the mark that
non-fast-forward pushes are permitted to the branch.
Signed-off-by: NDmitry Potapov <dpotapov@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>