Add missing delete messageCentral in dtor
Fix minor comment typos
Simplify code in Router class
Minor optimization in Router::closeControlSocket and Router::closeDataSocket
Set Router::persistState() as const
Minor formating and typos fixes
Set unavailableIdsLock as mutable and as Router::isElementAvailable as const
Bunch of code simplifications and formatting fixes
Factorize close control and data socket into Router::closeSockets
Improve comments + fix some minor code formatting
Add missing std namespace
Fix constness in MessageCentral and inherited classes
Merge pull request #1000 from ngeiswei/improve_router

Improve router, mostly fix const and add comments