Reflog support status

My recent flurry of patches tonight (looks to be 5 total, 6 counting the user.name/user.email bug fix) should now include reasonably useful information messages anytime a ref which has an associated reflog gets updated, unless the update was made by one of the following:

	git-archimport
	git-cvsimport
	git-svnimport
	git-receive-pack

Which is pretty reasonable.

I'll try to tackle git-receive-pack tomorrow night, but the reason I have been putting it off is it would die a horrible death (exit anyway) if it attempts to update a logged ref and GIT_COMMITTER_IDENT can't be determined. But if the repository owner has enabled reflogging exiting is probably the right thing to do in that case...

I'd also like to parameterize git-am's reflog entries the way I did with git-merge, this way git-rebase will report as 'rebase' in the log rather than 'am'. Again, I'll see if I can get that done tomorrow night.

Junio: do you happen to still have that reflog program you put
together?  I'm wondering if maybe we shouldn't include a git-reflog
to cat the reflog file in a more human friendly format than the
timestamps contained within the file, not to mention maybe also do
oneline commit pretty printing.