added diamond selfmon feature
add: senddata method for unittest, bugfix: Metric.__repr__ already adds newline, so removed join newline separator
unittest for graphitehandler, including backlog tests
added warn log for backlog trimming
Merge pull request #255 from rtoma/graphite-handler-unittest

Graphite handler unittest + batch join bugfix
MongoDBCollector: allow restricting database list
Merge pull request #256 from knyar/mongo_databases_regexp

MongoDBCollector: allow restricting database list
PEP8 fixes
Merge pull request #252 from rtoma/processmemory-selfmon

added diamond selfmon feature
PEP8
Remove unneeded import, fix python path and add coding
Add in a service time test