Add Flashing LED During Update Process
Release v1.2
Merge v1.2 release branch back into master

I had originally intended to rewrite the LED blinking code
before v1.3, hence the separate release branch, but I haven't
had time yet and maintaining multiple release branches is more
trouble than it's worth, so I'm merging the current blinking
solution into master and will just revert it when I get around
to the rewrite.
Update splash screen text for LED blinking