CORE: Brainstorming on ideas how to extended Xemu's core for audio sync/timing/emulation

[lgblgblgb]

Till now, Xemu for any emulated machine has no sound emulated, or if it has (like C65, Mega65) is totally incorrect, because (only key points):

• not integrated into the core framework, and handled per emulated machine level
• audio samples are "rendered" on out-of-audio-buffer SDL events, for the needed samples, thus any finer change would not apply (eg digi playback is not even possible in a sane way, also like SID tricks with more rapid register changes won't be taken account at all, since only SID registers at the time of the rendering is taken account)

[lgblgblgb]

The "mother" of this bug was still present in the Xep128 project: #157 (Xep128 transferred issue).