Bug 1312 - msg-spy config validation fix

* fix for commited  BugFix 542 - Plugin internal stats
* fix for forgotten TODO task (initialization method in PluginProvider)

* refactoring for internal statistics
* add internal statistic confSubsystem module
* add MXBean for statistic's report

Change-Id: I1e734063396b2e5344ebd755fde19cea85ac1490
Signed-off-by: Vaclav Demcak <vdemcak@cisco.com>