Merge branch '1.4.5-SNAPSHOT' of https://git-wip-us.apache.org/repos/asf/accumulo into 1.4.5-SNAPSHOT
ACCUMULO-2378 Replace LOGNAME usage in TestUtils.py with getpass

When running functional tests under MapReduce, the LOGNAME environment variable is
not available. This change switches TestUtils.py to use getpass.getuser(), which
looks for a variety of environment variables to locate the current user, and which
works more reliably.
Merge branch '1.4.5-SNAPSHOT' into 1.5.1-SNAPSHOT