_getRuntimeSettings(): Dte2/Cfg & invoc. optimization

* TRuntimeSettings updated with the IVsUpdateSolutionEvents.OnActiveProjectCfgChange
fixed _isActiveConfiguration - uses the SolutionContexts

* http://msdn.microsoft.com/en-us/library/envdte.solutioncontext.aspx
** http://msdn.microsoft.com/en-us/library/envdte.solutioncontexts.aspx
* http://msdn.microsoft.com/en-us/library/envdte80.solutionconfiguration2%28v=vs.120%29.aspx

maybe the problem #5 also was solved
patch 2 public release

* FIXED: Incorrect check configuration from the "Configuration Manager".
         Possible bug - "MSBuild Properties are empty not listed and used"