Various fixes for building on linux

[lanodan]

• CMake: Remove hardcoding of C & C++ compiler executables
• Rename min/max to MIN/MAX
• CMake: Use string-append rather than list-append for flags
• osiris_import.h: Don't redefine size_t
• netcon/includes/inetgetfile.h: Comment <linux/ipx.h>
• Chttpget.cpp: Fix return type
• CMake: Add -std=c++98 to C++ flags

[ei-grad]

Doesn't build :-(

[  7%] Building CXX object d3music/CMakeFiles/d3music.dir/musicapi.o
/home/ei-grad/repos/github.com/kevinbentley/Descent3/d3music/musicapi.cpp:167:58: error: macro "MIN" requires 2 arguments, but only 1 given
  167 |   const float kEpsilon = std::numeric_limits<float>::MIN();
      |                                                          ^
In file included from /home/ei-grad/repos/github.com/kevinbentley/Descent3/d3music/musicapi.cpp:3:
/home/ei-grad/repos/github.com/kevinbentley/Descent3/lib/Macros.h:54: note: macro "MIN" defined here
   54 | #define MIN(a, b) (((a) < (b)) ? (a) : (b))
      | 
/home/ei-grad/repos/github.com/kevinbentley/Descent3/d3music/musicapi.cpp: In function 'void D3MusicSetVolume(float)':
/home/ei-grad/repos/github.com/kevinbentley/Descent3/d3music/musicapi.cpp:167:54: error: 'MIN' is not a member of 'std::numeric_limits<float>'
  167 |   const float kEpsilon = std::numeric_limits<float>::MIN();
      |                                                      ^~~
At global scope:
cc1plus: note: unrecognized command-line option '-Wno-address-of-temporary' may have been intended to silence earlier diagnostics
make[2]: *** [d3music/CMakeFiles/d3music.dir/build.make:76: d3music/CMakeFiles/d3music.dir/musicapi.o] Error 1
make[1]: *** [CMakeFiles/Makefile2:1200: d3music/CMakeFiles/d3music.dir/all] Error 2
make: *** [Makefile:136: all] Error 2

[Lgt2x]

ef1c30a conflicts with #23

[winterheart]

There numerous merge conflicts already. It's worth to wait #45 and try on base of main branch.

[JeodC]

ef1c30a conflicts with #23

@lanodan Can you rebase and resolve?

[GravisZro]

So I've reviewed each commit in this PR and each one has already been fixed by another PR. You can safely close this PR with merging.