Better exception handling when instantiating YangModelBindingProvider, fix confignetconfconnector activator.

Do not just log exception if it occurs while calling getModuleInfo, but add it as nested exception.
Fix confignetconfconnector activator: if activator fails to find ConfigRegistry, stop method should interrupt searching for it.

Change-Id: I0b97e5a044be0fd2304b35d34f46a1c540aac248
Signed-off-by: Tomas Olvecky <tolvecky@cisco.com>
Merge "Better exception handling when instantiating YangModelBindingProvider, fix confignetconfconnector activator."