Fix an off-by-one bug with MCI_STATUS_LENGTH.

Wine crashes.

might not have an X11 window yet).

printing functions.

or charExtra are non-zero.

unextended equivalent of the key, plus the extended flag.

Windows sets 0x1400 in such cases for programs.

A few more parameter validation checks.
Return DS_OK rather than 0 in a number of functions.
Fixed primary buffer ref count bug in CreateSoundBuffer().
Handle 1-3 byte sound fragments that would cause buffer overruns.
Clear primary buffer with a neutral value instead of always 0
(because 128 is neutral for 8-bit sound).
Fix bug with mixing 8-bit sound into the primary buffer.
Broke out the main block in DSOUND_thread() to another function for
readability.
Handle "no audio" and "audio busy" cases properly when initializing
dsound. Rename DllCanUnloadNow() to DSOUND_DllCanUnloadNow().

- [GS]etSelectorBase Win32s offset support by Ulrich Weigand (thanks v.m. !!)
- Move AppToWine/WineToApp macros as W32S_APP2WINE etc. to ldt.h
- LocalNotify() basic support
- Fixes for local heap handling with heap handles created by Virtual*()

done yet and more for testing purposes.