Minor inconsistency: "git tag" requires space after -m.

Hello,

It seems options parsing is somewhat broken in git-tag:

$ git tag -a -m"Annotated tag" annotated-tag usage: git-tag [-n [<num>]] -l [<pattern>] | [-a | -s | -u <key-id>] [-f | -d | -v] [-m <msg> | -F <file>] <tagname> [<head>] $ git tag -a -m "Annotated tag" annotated-tag $ git --version git version 1.5.3.4

This is inconsistent with, say, "git commit", that groks -m"Message" (without space after -m) just fine.