The fOpRedundant field of the GlyphIndex primary drawing order
(MS-RDPEGDI, chapter 2.2.2.2.1.1.2.13) was neglected which resulted in some
severe text rendering errors.
* Zeroing xevent helped address some erratic behavior.
* valgrind complained about using xfBitmap uninitialized
during shutdown, traced it back to the initialization.
Bitmap_Prototype->size > sizeof(rdpBitmap).
* Early exit from recv_tpkt_pdu is necessary to address
a shutdown crash - the channelId value was being used
without being set in the disconnect case.
