UC-1219 - Make the log format configurable
 -LoggerBase:
    -added an extra class variable : a set of active filters
    -the log format is received as a string; the string is parsed and the filters are added in the
     set of active filters
 -Added LogBaseFilter class :
    - base class from which all the other filters derive
    - to see if a filter is enabled we check if it is in the set of active filters
 -Each "filter" method from te derived filters now checks to see if the filter is enabled

 -changed main source files for sipXpark sipXproxy, sipXpublisher, sipXregistry, sipXrls, sipXsaa
 in order to support log format configuration

 -the set of active filters is specified in the config file; if the filters aren't specified
 we have the default behaviour. The delimiter between the filters is ","