Blender Git Loki

SCons updates
* Almost all library settings are now available in the config.opts user option
file.
* All platform variables had to be updated to make this possible. Things are
much clearer now, but I only was able to test the changes on Linux. I've
tried to update all other platform variables, but things are most likely to
be broken. Please contact me how to resolve the issues.


Note: Before running scons, remove your existing config.opts file to get all
new options.