add additional information to callback interfaces

commit fd2d612777424fd7e4ec2c488ee6999eaffa2fb8
Author: Gabriel Young <gabeplaysdrums@live.com>
Date:   Sat Jun 28 18:17:10 2014 -0700

    add ui to enable/disable debug overlays

commit 63ea8362ac7d2378d6adb0e60fa81138d08fe16b
Author: Gabriel Young <gabeplaysdrums@live.com>
Date:   Sat Jun 28 17:49:08 2014 -0700

    invoke step callback after updating the simulation

commit 10bea323c36e3c27cd43a6c09c71cdc56db1f1ee
Author: Gabriel Young <gabeplaysdrums@live.com>
Date:   Sat Jun 28 14:45:06 2014 -0700

    started updating sample to avoid friendly tanks

commit e6f60cdf275de8b43e90d21355f2a97f87225225
Author: Gabriel Young <gabeplaysdrums@live.com>
Date:   Sat Jun 28 13:20:52 2014 -0700

    move bounds detection into a common function

commit e8c0b522b48ec2ef3ea30009d0e4092868bed6f8
Author: Gabriel Young <gabeplaysdrums@live.com>
Date:   Sat Jun 28 13:15:21 2014 -0700

    include bounding box of the tanks in the world

commit 839126849e776bed7c3f1fab7f7fe64ff6be20d6
Author: Gabriel Young <gabeplaysdrums@live.com>
Date:   Sat Jun 28 09:19:19 2014 -0700

    don't start the sim when applying new code

commit 5dbd408948581aa12ad7026554ce5a754dc81cd8
Author: Gabriel Young <gabeplaysdrums@live.com>
Date:   Sat Jun 28 09:11:51 2014 -0700

    remove hard coded values from sample and fix bugs

commit bf7d8da9a64fa049d3e41aa80eea990a82faeca7
Author: Gabriel Young <gabeplaysdrums@live.com>
Date:   Sat Jun 28 08:59:56 2014 -0700

    print the time user code was applied in the conosle

commit d8dee237e0f36be78afdaba24e67f4216de62025
Author: Gabriel Young <gabeplaysdrums@live.com>
Date:   Sat Jun 28 08:48:49 2014 -0700

    add an __init__ callback

commit 9db4cd53dfdac4a21bc2c1af3aa6da409b133a9d
Author: Gabriel Young <gabeplaysdrums@live.com>
Date:   Sat Jun 28 08:20:19 2014 -0700

    add a comment to the sample