add filter to ignore log files
Implementation of jdbc monitoring (not only for net.codjo.mad.server.handler.Handler) :
- in *Spy classes, each call to System.currentTimeMillis() is replaced by a call to TimeSource.getTime()
- new features for JdbcManager :
    * manage a set of connection factories (implementations of ConnectionFactory interface)
    * manage a set of listeners (implementations of ConnectionPoolListener interface) receiving events from the ConnectionPool