[bind10-1.2-release] bump version
[bind10-1.2-release] add release date
[bind10-1.2-release] update release version
[bind10-1.2-release] change README to contain my release notes instead

Use my release notes (announcement) for README instead.
Okayed by Stephen via jabber.
[master]Merge branch 'master' of ssh://git.bind10.isc.org/var/bind10/git/bind10