ACCUMULO-2126 Hadoop profile names should be consistent across branches.

Changes naming scheme to be by Hadoop generation, i.e. hadoop-1 and hadoop-2.

Adds ability to either rely on default or to specify default by profile, i.e. hadoop.profile=1 on 1.4.

Adds a more helpful error message when the provided hadoop.profile doesn't match one of our expected options.

Signed-off-by: Mike Drob <mdrob@cloudera.com>