Fix issue #33, exclusive mode focus on Linux.
Fix issue #33, exclusive mode focus on Linux.

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