change history for 1.2

[Justin C. Sherrill]

Any objection to me adding this:

<p>
A <a
href="http://leaf.dragonflybsd.org/releaseinfo/DragonFly_RELEASE_1_2.txt">detailed
commit history</a> is available.
</p>

between the errata and release sites sections on
http://www.dragonflybsd.org/main/release1_2.cgi ?