Fix to Diameter RAs fail to set/cancel ActivityRemoveTimer in a clustered environment

Update Issue #8
- Configured FT Timer before using it
- Moved timer task data to a single class, to avoid serializing objects in excess
Fix/Enhancement to Diameter RAs fail to set/cancel ActivityRemoveTimer in a clustered environment

Update Issue #8
- Catching and logging exceptions when thrown setting/cancelling ActivityRemoveTimer
Forcing maven surefire plugin to use JUnit instead of TestNG (from SCTP)
Updating HSS Enabler dependency on Sh Client RA Type
Updating HSS Enabler dependency on Sh Client RA Type
Forcing jain-slee-11-ext version as parent has SNAPSHOT
Forcing jain-slee-11-ext version as parent has SNAPSHOT