Move midi implementation to user mode

[pachuco]

Midi implementation in win2k kernel mode + user-provided file is a rather dangerous combination.

Mostly because the midi implementation doesn't sanitize the bank format. At least, I've gotten the NT4 extracted implementation to crash program with garbage data(reading bank out of a naked malloc, lol).

Adition to suggestion, user mode component should send FM writes one buffer at a time(flushing) to reduce context switches.

Of course, as a bonus, this lets the user diddle with the implementation.

[leecher1337]

Not much we can do about it, Win2k driver architecture is like it is.

NT4 did a lot of stuff in Usermode, even GDI (via CSRSS), which sucked big time, because it's insanely slow, that's why i.e. GDI also was moved to kernel mode in Win2k (Win32k.sys) and the stupid concept with running all the stuff in usermode was given up.
I guess the same applies to sound architecture.

[pachuco]

Then maybe at least, sanitation for patches loaded from file. This comes to mind:

1. Check if bank filesize is at least the size of offset table(2 * 128 * sizeof USHORT).
2. For each offset, check if offset(relative to 0 or table end? I forgets) + patch size(36 or 72) <= filesize.