Add option to not set antialiasing

Sometimes antialiasing causes unwanted effects, for example on linux, the mesh of my floor model is visible when antialiasing is turned on:

![screenshot-fri-mar-14-14-58-48-2014-63](https://f.cloud.github.com/assets/83444/2426340/ef094130-abc3-11e3-8c3f-9c99c8d244e5.jpg)

This pull request just adds a new configuration option (default set to true) for whether to turn on antialiasing or not.