completion: introduce __gitcomp_nl_append ()
There are situations where multiple classes of completions possible. For
example
branch.<TAB>
should try to complete
branch.master.
branch.autosetupmerge
branch.autosetuprebase
The first candidate has the suffix ".", and the second/ third candidates
have the suffix " ". To facilitate completions of this kind, create a
variation of __gitcomp_nl () that appends to the existing list of
completion candidates, COMPREPLY.
Signed-off-by: Ramkumar Ramachandra <artagnon@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>