* According to MS-RDPBCGR 2.2.7.1.5 the pointerCacheSize is optional
and its absence or a zero value indicates missing client support for
the New Pointer Update.
* Added and fixed some comments regarding the meaning of the KBDFLAGS_DOWN
keyboard flag and how it is currently used in the code.
"Fixed" the slow path keyboard input to generate the same keyboard flags
as the corresponding fast path code.
* Some arbitrary value was used for the ConnectPDULength in the GCC
Conference Create Response. According to MS-RDPBCGR 4.1.4 this value must
be ignored by the client so we encode a zero value instead.