Don't send unnecessary list management updates to OSCam

This commit fixes sending updates to OSCam eg with the following flow:
DVBAPI: 0.0 set CAM decrypt (SID X, caLm 4, HasCaDescriptors 0)
DVBAPI: 0.0 set CAM decrypt (SID X, caLm 5, HasCaDescriptors 0)
Fix plugin initialization and shutdown order

SocketHandler was sometimes trying to write to uninitialized
DeCSA. Correct order of creating and deleting objects.

Valgrind:
==31812== Invalid write of size 1
==31812==    at 0x847CB1F: DeCSA::SetCaPid(unsigned char, ca_pid*) (DeCSA.cpp:132)
==31812==    by 0x847D91C: SocketHandler::Action() (SocketHandler.cpp:151)
==31812==    by 0x50246E: cThread::StartThread(cThread*) (thread.c:262)
==31812==    by 0x5075E0D: start_thread (pthread_create.c:311)
==31812==    by 0x667A0FC: clone (clone.S:113)
==31812==  Address 0xf2145af is not stack'd, malloc'd or (recently) free'd