Improve description of git-branch -d and -D in man page.
Improve description of git-branch -d and -D in man page.

Some users expect that deleting a remote-tracking branch would prevent
fetch from creating it again, so be explcit about that it's not the case.
Also be a little more explicit about what fully merged means.

Signed-off-by: Jan Hudec <7ca6c1515a632399abd113f1793579697ae5a315@ucw.cz>
Signed-off-by: Junio C Hamano <a6723cc3f76163bf7adb636a73ac3b0ceb3e6b9b@pobox.com>

destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git