HAMA-867: change url to maven central repository

git-svn-id: https://svn.apache.org/repos/asf/hama/trunk@1571556 13f79535-47bb-0310-9956-ffa450edef68
maven seems update required dependencies automatically.

git-svn-id: https://svn.apache.org/repos/asf/hama/trunk@1571564 13f79535-47bb-0310-9956-ffa450edef68
delete useless codes 

git-svn-id: https://svn.apache.org/repos/asf/hama/trunk@1571961 13f79535-47bb-0310-9956-ffa450edef68
HAMA-878: PartitioningRunner.Sorter doesn't allows duplicate key

git-svn-id: https://svn.apache.org/repos/asf/hama/trunk@1572838 13f79535-47bb-0310-9956-ffa450edef68
HAMA-878: PartitioningRunner.Sorter doesn't allows duplicate key

git-svn-id: https://svn.apache.org/repos/asf/hama/trunk@1572839 13f79535-47bb-0310-9956-ffa450edef68
Merge branch 'trunk' of git://git.apache.org/hama into trunk
HAMA-879: Errors for messages with wrong destination should be more clear (Anastasis Andronidis via edwardyoon)

git-svn-id: https://svn.apache.org/repos/asf/hama/trunk@1573268 13f79535-47bb-0310-9956-ffa450edef68
HAMA-880: Check whether input records are in order by vertex ID (edwardyoon)

git-svn-id: https://svn.apache.org/repos/asf/hama/trunk@1573269 13f79535-47bb-0310-9956-ffa450edef68
Fix toString() method.

git-svn-id: https://svn.apache.org/repos/asf/hama/trunk@1573446 13f79535-47bb-0310-9956-ffa450edef68
Merge branch 'trunk' of git://git.apache.org/hama into trunk