Heads-up: beta git repo hashes changing this weekend

[Ed Maste]

We're going to make sure to keep the svn2git-converted beta repo
hashes consistent for at least 2 week periods at a time, so that
developers and testers can experiment without the hashes changing
underneath them unexpectedly.

That said, uqs@ has some pending changes to the converter and so the
beta repo hashes will change this Sunday, July 19.