fixing bug #5668 Message incorrect lors d'un défaut de login lié au domaine de connexion
Bug #5997: fixing some problems
- refactoring the code
- using centralized treatments around WYSISYG (WysiwygController)
- adding a transformer class for WYSISYG
- adding unit test on new tools
- adding new method on URLManager to provide anywhere in the code the server URL

Conflicts:
	web-core/src/main/java/org/silverpeas/servlets/SilverListener.java
Bug #5668 : fixing a NullPointerException
(fixing a unit test compilation problem)