A little bit of cleanup mostly poached from a WIP branch.
A little bit of cleanup mostly poached from a WIP branch.

Remove no-longer-needed includes and streamline typedefs/using directives.

feilen/OSVR-Core,OSVR/OSVR-Core,OSVR/OSVR-Core,leemichaelRazer/OSVR-Core,godbyk/OSVR-Core,godbyk/OSVR-Core,godbyk/OSVR-Core,leemichaelRazer/OSVR-Core,godbyk/OSVR-Core,godbyk/OSVR-Core,leemichaelRazer/OSVR-Core,feilen/OSVR-Core,OSVR/OSVR-Core,OSVR/OSVR-Core,godbyk/OSVR-Core,feilen/OSVR-Core,OSVR/OSVR-Core,feilen/OSVR-Core,leemichaelRazer/OSVR-Core,leemichaelRazer/OSVR-Core,OSVR/OSVR-Core,feilen/OSVR-Core