Use ncalrpc instead of ncacn_np as the transport as this is more similar
to how ole32 from NT works and should also be compatible with rpcrt4
from Win9x, allowing more combinations of dlls to work.

widl: Only assign variables if not a string and only create a local variable if not a sized parameter.

Only assign variables if not a string and only create a local variable
if not a sized parameter. Fixes type mismatches in the generated code
due to differences in the algorithms between creating local variables
and using them.

widl: Initialise the temporary variable to 0 for parameters with more than one level of indirection.

Move handling of base type marshaling and unmarshaling to a separate
function and improve it to support return values.