make it possible to build without GL, without GTK, without ncursesw, without ncurses

by default, libgraphics.so pulls in a whole bunch of stuff, especially with gtk enabled.

my goal was to make GL optional, but in order to so i had to address the other issues as well.

before this PR, it was not possible to build without missing ncursesw, now it's detected by scons if it's available and falls back to ncurses without widechar support if not. same for gtk and GL.

i also pulled in the upstream codechanges from the source distributed in 34.11, as well as some work by @philippelatulippe (there's one fix which removes the only usage of C++11 features, so it can be compiled with a compiler that is compatible to the libstdc++.so used by the game itself.). he also did the work to make GTK+2 optional.