migrated from Update() to coroutine

As I've mentioned in my forum post, I've migrated away from using Update() to a coroutine. More details in the forum post [here](http://forum.kerbalspaceprogram.com/threads/50858-0-21-GHud-Adds-displays-to-built-in-screen-on-Logitech-G19-G510-keyboards-%28v1-2%29?p=1285430&viewfull=1#post1285430).