glemu deadcode and macro purge

[ghost]

Each line was removed, one by one, check that the compilation passed.
On Debian 10, with clang++ and some custum setup, all passes. CI will
check that all damn systems builds. It's the only thing it's setup for,
after all.
I will not apply ANY codestyle or doc patch on this, because it's just
a damn cleanup, not real changes.
To redo:

• 1: apply cpp on your target
• 2: n = 1
• 3: until EOF
• 4: remove line 1
• 5: build
• 6: if build failed, cancel 3
• 7: n++
• 8: goto 3

[ghost]

FYI: I don't intend to do any code style related change on this. It's something that a tool could have do, but I know none that is able to do that automatically, so I did it (partially, cpp helped a lot) manually.
It's damn annoying, but at least, the code is now minimal, and there are no longer macros for nothing.

[voidanix]

If this PR is a "just remove the macros mechanically" one, then we can clean this up later with real code changes.

#250 should take care of code-style changes down the road.