Updated Titan configs used in Expect-based ITs
Remove {mapred,core}-site.xml from <ziproot>/conf

Following a suggestion from Daniel, I've removed the core-site.xml and
mapred-site.xml files with comments and a couple of stub config
values.  Users who already have Hadoop installed have likely already
customized their mapred-site.xml and core-site.xml under their
$HADOOP_PREFIX or $HADOOP_HOME.  Putting copies of these in conf just
raises the potential to silently mask the user's preferred mapred- or
core-site.xml with some almost-empty defaults from Titan.

gremlin.sh has also been updated to look for both Hadoop 1 and Hadoop
2 config file directories instead of just Hadoop 1 config file
directories.
Fix ES version tested with 0.5.0 in changelog