Revert "ACCUMULO-2125 - bumping up guava"

reverting until classpath issues in MAC are resolved

This reverts commit 1a9ae3cccf9e390ed6a6019a38fb3ee30965572a.
ACCUMULO--2134 Catch the case where we get the TNFE wrapped in an AccumuloException
Merge branch '1.6.0-SNAPSHOT'