Removed test_Data and added it to gitignore.

Signed-off-by: Ken "Minalien" Murray <minalien@gmail.com>
Removed Standard Assets (& skyboxes).

Signed-off-by: Ken "Minalien" Murray <minalien@gmail.com>
Removed source art.

Signed-off-by: Ken "Minalien" Murray <minalien@gmail.com>