Refactored AbstractService

- AbstractService no longer specifies a period, "serve" is endlessly
called when finished
- AbstractPeriodicService added as a subclass defining a delay between
between previous "serve" return and next "serve" call
Refactored and renamed UBPE2012TCPRelayWelcomeDataEventReader Service

- renamed UBPE2012WebFrontEndWelcomeService
- refactored as a subclass of AbstractService
Fixed UBPE2012RelayServerMain according to
UBPE2012WebFrontEndWelcomeService refactoring
Removed references to period in AbstractDataEventListenerService
Removed references to period in
AbstractFileBuilderDataEventListenerService
Fixed UBPE2012JsonProducerDataEventListenerService according to
AbstractFileBuilderDataEventListenerService modifications
Renamed UBPE2012RelayServerMain to UBPE2012WebFrontEndServiceLauncher
Renamed UBPE2012TCPRelayWorkerDataEventReaderService to
UBPE2012WebFrontEndDataEventParserForwarderService
Fixed start/end of token in UBPE2012JsonProducerDataEventListenerService
Refactored and renamed AbstractTextFileTransformationService

- refactored as a subclass of AbstractPeriodicService
- renamed to AbstractTextFileTransformationPeriodicService
Renamed JsonFileTokensRemoverService to
JsonFileTokensRemoverPeriodicService
Fixed some classes according to previous refactorings

- UBPE2011RelayServerMain
- UBPE2012WebFrontEndServiceLauncher
- JsonFilteredFileProducerService
Moved to a more generic design and reorganised files

- Web front end client and server part are now more generic. event types
and associated parsers are taken as constructor parameters
- Some useless classes have been removed
- Some classes and packages have been renamed 
- Application launchers have been modified according to refactorings
Merge branch 'develop'

Conflicts:
	src/fr/iutvalence/ubpe/ubpe2012/services/UBPE2012JsonProducerDataEventListenerService.java