So they don't mess with shell scripts that expect SRB2 to exit when it crashes (like most other programs)

I found this easier than trying to adjust the makefile, as it uses the same thing to automatically generate the various NO* compile options.

- target_sources from correct directory
- enable_language must be used in add_executable directory

This establishes (near) parity of source code file lists
between the Makefile and CMakeLists.txt

To make that change I messed around CMakeLists.txt a bit.
It now uses target_sources and target_compile_definitions.
I also removed some MSVC stuff since we don't actually
care about MSVC--it made things easier.

CMake minimum version 3.0 -> 3.13 for target_sources.

Some key points for programmers:
- Source code files are mostly listed in a 'Sourcefile'.
  So you no longer directly edit the object list. There
  can be multiple Sourcefiles and they can even live in
  subdirectories--the directory name will be prepended to
  every filename in the list. Of course, the Makefile
  still needs to be edited to read from each Sourcefile.
- Different rules are no longer required for source code
  files that live in subdirectories (such as sdl/ or
  hardware/). Subdirectories Just Work so go ham!

In addition to those points, another important change is
that the bin directory is no longer divided into platform
subdirectories (Linux64, Mingw, etc). Executables now go
directly into bin. If you use DEBUGMODE or target 64-bit,
then subdirectories for 'debug' and '64' will be made
though.

Oh by the way, I don't think make clean actually removed
files before on Windows. It should now. I also fixed as
many little inconsistencies like that as I noticed.

And now just an overview of the technical aspects that
shouldn't affect anyone who doesn't REALLY care about the
Makefile...

objs and dep directories have been moved to a make
directory. Makefile.cfg and its variants have been moved
out of their various subdirectories to src/Makefile.d
make distclean removes the bin and make directories
entirely, but make clean and cleandep still only affect
the current build target.

When I say automation, I mean that a lot of copy pasting
in the Makefile has been reduced.

I also put in a missing `defined (__APPLE__)` in d_netcmd.h related to cv_mouse2opt

Also removed a redundant `!defined (__APPLE__)` in d_main.c

Indirectly fixes the game doing whatever after freeing a patch.
This commit implements a FTextureInfo struct type, instead of it being a typedef to the GLMipmap_s struct type.

I made the assumption it would always be defined, which won't always be the case.

* Hooks are no longer a mess of lua boiler plate. Helper functions reduce hooks
  to, at the most basic level, only two calls.
* Lua tables (the array part) are used to index hooks. Such tables contain only
  hooks of the same type.
* Hook types are defined in one place so you no longer need to sync up the enum
  and name array.