git-log: put space after commit mark

git-log: put space after commit mark

Currently, commit marks (left, right, boundary, cherry) are output right
before the commit sha1, which makes it difficult to copy sha1s. Sample
output for "git log --oneline --cherry":

=049c269 t6007: test rev-list --cherry

Change this to

= 049c269 t6007: test rev-list --cherry

which matches exactly the current output of "git log --graph".

Leave "git rev-list" output as is (no space) so that they do not break.

Adjust "git-svn" which uses "git log --pretty=raw --boundary".

Signed-off-by: Michael J Gruber <git@drmicha.warpmail.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>