The "cannot be null" attibute is applied to a parameter if and only if 
it is in-only.

Add some tests for this.

Add a test for this function.

It doesn't matter whether or not the array is declared as a pointer or 
is declared using array subscripts - the array is still allocated by the 
unmarshalling function and so needs to be freed.

Fix a typo that caused varying arrays never to be freed.

Fix another typo with the check for conformant arrays being performed 
twice, redundantly.

imm32: ImmNotifyIMM with CPS_CANCEL fully clears the composition string. Also enable respective tests.

rpcrt4: Print fixme's if the serialize or no-serialize flags are set on a context handle being marshalled or unmarshalled.

rpcrt4: Pass the interface identifier to the lower-level context handle routines for context handles with the strict flag set.

widl: Output calls for the new versions of the marshalling and unmarshalling routines for server context handles.

This needs to be done to match the call to NdrContextHandleInitialize 
and because we default to using strict context handles.