Re: [WISH] Store also tag dereferences in packed-refs

Linus Torvalds [off-list ref] writes:

So I'd suggest adding - at the very top of the ref-pack file - a line line

	# Ref-pack version 2

which will be ignored by the current ref-pack reader (again, because it's 
not a valid ref line), but we can use it in the future to specify further 
extensions if we want to.

Now somebody would just need to implement that ;)

For this particular one, there is no need for version 2.

My current wip does:

	SHA-1 SP name LF
	SHA-1 SP SP name^{} LF

the latter of which is ignored by code in the wild and the new
code can take advantage of (and fall back the usual deref_tag
when it is not available).

I need to rebase it on top of a minor update to refs.c before
pushing it out.