AddinManager: Removed unused variable and proper method isolation (public -> internal)
AddinLoader/AddinManager: Support for addin start/stop management.

Start/Stop method implemented in AddinManager. Addin Loader methods
moved to a separate Service Layer (AddinLoader Services), because
in ContainerManager now we instantiate AddinManager allways as the
Inception AddinManager, even if we're running inside an addin AppDomain.
SAPServiceFactory: Fixed bug on inception company.

The variable isConnected wasn't correctly setted. Fixed it.
Form/Admin: Support for start/stop addins at runtime.
AddInStartupManagement: bug on dependency injection.