* Bug fix for eye tracking in HMD, the "up" orientation of your eyes now match your head.
* DebugDraw: added drawRay method.
* Application: Renamed preRender to postUpdate
* AvatarManager: added postUpdate method that iterates over all avatars.
* MyAvatar: Renamed preRender to preDisplaySide
* MyAvatar: split preRender code into postUpdate and preDisplaySide.
* Removed "Show who is looking at me", "Render focus indicator" and "Render lookat target" debug draw.
* Split "Show Look At Vectors" into "Show My Look At Vectors" and "Show Other Look At Vectors", to make it easier to debug eye tracking.
* "Show Look at Vectors" now draws the right eye red and the left eye blue.
* Removed Avatar and MyAvatar renderBody
* Removed look at rendering from head.
* GLMHelpers: Bugfix for generateBasisVectors when up primary and secondary axis were orthogonal
static variables used to hold a Singleton cannot be shared across dll boundaries by default.
This uses the globalInstance template to store the instance as a property on the QApplication.
