tag: accept multiple patterns for --list

tag: accept multiple patterns for --list

Until now, "git tag -l foo* bar*" would silently ignore the
second argument, showing only refs starting with "foo". It's
not just unfriendly not to take a second pattern; we
actually generated subtly wrong results (from the user's
perspective) because some of the requested tags were
omitted.

This patch allows an arbitrary number of patterns on the
command line; if any of them matches, the ref is shown.

While we're tweaking the documentation, let's also make it
clear that the pattern is fnmatch.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>