- True multiple dimension array / strings in arrays support

- compatibility mode for generating MIDL-readable data:
 - strip out pidl-specific properties
 - convert subcontext() to an array of uint8.
 - perhaps replace subcontext() with something more generic? The argument
 to subcontext() isn't really intuitive at the moment

- don't be so strict on array boundaries.. arrays can and will be empty when 
  a (regular) remote error occurs
 
- support nested elements