Added new Endpoint_Null_Stream() and Pipe_Null_stream() functions.
Removed the NO_STREAM_CALLBACKS compile time option due to the new partial stream transfer feature replacing it.
Fixed errors in the incomplete Test and Measurement device demo preventing proper operation (thanks to Pavel Plotnikov).
Add GCC_FORCE_POINTER_ACCESS() macro use to the RingBuffer library header, to attempt to force GCC into producing more efficient code for manipulating the buffers.