Remove the obsolete StatisticsMonitor

a) It's empty, not implemented
b) It's designed wrong, it should use signals like everyone else.
Removing extra mutex lock in ClassServer::getNumberOfClasses() - not needed
Merge pull request #278 from TNick/classerver

Removing extra mutex lock in ClassServer::getNumberOfClasses() - not needed
Remove obsolete API

This code never did anything, anyway.
Merge pull request #279 from linas/kill-stats

Kill StatisticsMonitor
Merge branch 'master' into doxydoc