[Gzz] 7th (jvk)

[Janne Kujala]

7th: libpaper and gldemo framework work

Made gfx.libpaper.textures cache all generated textures
and remake *.bin files from changed *.texture files.
Removed all execfile()'s from libpaper and moved out
slow initialization from module init time.

Now that execfile is no longer used, there needs to be some 
other way to get changed files reloaded without restarting.
I changed gldemo.py so that "r" reloads all gfx.* modules. 
Takes about a second with papertest.

The my_import calls in libpaper now do just a standard import.

[ I first implemented gfx.libutil.myimport.my_import function
to reload any changed files when a module was reimported, but
it did not work very well because of unknown file dependencies 
(gfx/libtexture/*.bin files were not remade if textures.py
was not changed) ]

        jvk