ALLJOYN-2501: Extended AJ_MarshalArgs() & AJ_UnmarshalArgs() to support struct, dict-entry, variant, and scalar array signatures. Updated aj_bus.c and the mutter.c unit tests  to use the new functionality.
Comment clarifications
ALLJOYN-2509: Expose some internal msg arg function as APIs in a new header file aj_msg_priv.h
ALLJOYN-2501: gcc need to use a macro __va_copy() to copy va_list values.
restored old version of svclite
ALLJOYN-2511:  Need to clear the flags field in the parent so it doesn't appear that the object is hidden or disabled.