Merging changes from cegli:VR-Hydra branch and dolphin:master branch to CarlKenner:VR-Hydra branch

I've updated my branch to the trunk of dolphin:master, and also finished my X-Input polling.  Some fixes to the make files for Linux have happened as well, courtesy of Feilen.  A define has been added to change between 0.4.2 and 0.4.3.  There were also changes to the Nunchuk.cpp, which broke your HydraTLayer.  I updated it in a way that I think would work, but can't test it.