- Update DUMB to revision c7aadf292975e96c3036fc4f2e4248a5c727fa5d

    - Fixed loop start for STK modules.
- Update DUMB to revision 9a68144bfcd970e257b37ccc001d58c23cbe007e

    - Changed panning rule from 3dB to 0dB to match most trackers
- Updated DUMB to revision 569b49a533a53b92dceac0eb6b4aa6641f65ae5e

    - Implemented support for compressed stereo samples
- Updated DUMB to revision cc986aa7dad019e2e4f8fe2d42013e50a1cd79d6

    - Fixed shit
Could not apply revision 8ba1f7e7c01eef9dac7dd79cf2026ae9c3364b8d but the other revision changed the same portion of code.
- Updated DUMB to revision 5f1d4388b1ba13ca80540f4734bbc58648468e3c

    - Removed *16/11 scale from S3M global volume
    - Applied S3M master volume as mixing volume
    - Renderer now ignores S3M Vxx for values greater than 0x40
- Updated DUMB to revision 4e0faec2b81698376b78c4715d633de23140cd10

    - renamed "restrict" parameters to "restrict_"

    - "restrict" is a keyword since C99

Actually it was already implemented, but with a different variable name. Anyways, it was not possible to apply the previous revisions, some because of FIR resampler, some because of the Lanczos resampler (introduced in 1eef4c9f892c119f2f92f0d928efe1b7a98af934) and some because of the surround mixer (introduced in b40d6a5877558121d876ee3c578daecf138b504c , not hard to merge but should be adapted to the custom code).
- Updated DUMB to revision 796c801be6b1db3a800a844ab58b9a5454951ace

    - Subsong scanner always tries to play the first order now

Yeah, still tons of commits were skipped because of the same kind of improvements to not-ported features.
- Updated DUMB to revision 9b377f8d7f76159d7f227c727aeae7e16fd1db7b

    - Cleaned up several warnings, including a buffer
      overflow in the DSMF reader

Also, fixed three Clang warnings (two in src/it/readmod.c, one in src/it/readxm.c) regarding the incompatible long<->int32 pointers passed as arguments, not caused by original dumb code.
- Updated DUMB to revision d2d6f48b2bdecc96a60c7e7dfab2b83bf72dc143

    Fixed another stupid error

It wasn't possible to merge properly because of the big changes done in zdoom, but two similar errors in the same part of the code were spotted and fixed, so it should be okay.
- Updated DUMB to revision 991ce8202643a296969d9a623e9702966a957e69

    - Moved DUMBFILE structure to its own header file to unify the rare cases where it needs to be visible outside of dumbfile.c

I skip f5a1c5ec318cd7c17fb54f2ed2cb70d72cd549f6 for now, since it's huge and full of conflicts, but it is IMO important and should be done ASAP.
- Updated DUMB to revision 0bc29b4eb63b5758cf0d174258b6b072a3041a33

    - various fixes to address GCC warnings

Some of the files contain already a similar fix, some are not here yet.