Fixes build linux x86_64

Fixes to `libfamitracker`
=============================================

These fixes allow `libfamitracker` to be build on a x86_64 Linux system—at least, on my system.

[Commit f89849b](
https://github.com/Jarhmander/nesicide/commit/f89849bd4bf36ed19600ad8e0d7abe8392e06e2f) contains the actual build fixes, [commit 19d60aa](
https://github.com/Jarhmander/nesicide/commit/19d60aa89d19e1c8d655a8298b118a2ceb43510a) is a small runtime fix; it removes a bogus assert in `Blip_Buffer.cpp` that is not present in the up-to-date Blip\_Buffer library. This assert prevents correct use of `libfamitracker`. 

Mainstream FamiTracker should apply the `UINT` → `UINT_PTR` fixes and use the latest Blip\_Buffer code.