HAMA-847: Vertex should provide Counters

git-svn-id: https://svn.apache.org/repos/asf/hama/trunk@1585363 13f79535-47bb-0310-9956-ffa450edef68
HAMA-855: Handling Address binding exceptions

git-svn-id: https://svn.apache.org/repos/asf/hama/trunk@1585418 13f79535-47bb-0310-9956-ffa450edef68
Merge branch 'trunk' of git://git.apache.org/hama into trunk