ACCUMULO-1643 Update the default hadoop-1 dependency from 1.0.4 to
1.2.1

Hadoop-1.2.1 is the most current, hadoop-1.x.y release, and, as such, we
want to make an effort to advertise to users that this is what they
should be using, in addition to receiving upstream improvements in our
unit and functional tests.
Merge branch '1.5.1-SNAPSHOT'