outputting to /.build (temp) and /.bin (final) instead of ../.bin
removed the premake option "quake3dir"
on Linux, not copying files if $QUAKE3DIR is undefined/empty
on Linux, compiling all C++ code with -std=c++98
added a meta-Makefile at the root for convenience
added build documentation (build.md)
use the "premake" tool from the cnq3tools repo with
"--quake3dir=<q3dir>" to generate a VS sln and gcc makefiles
this changeset also removes the "clever" handling of fullscreen/windowed
changes which didn't actually work and just broke windowed mode
