Use floor division for compatibility with Python 3
Use floor division for compatibility with Python 3

Thanks to Ryhor Salauyou for the patch.

Fixes issue #657.

theblacklion/pyglet,oktayacikalin/pyglet,oktayacikalin/pyglet,oktayacikalin/pyglet,oktayacikalin/pyglet,theblacklion/pyglet,oktayacikalin/pyglet,theblacklion/pyglet,theblacklion/pyglet,theblacklion/pyglet