v0.7.6 - Basic Gyro Support

Rewrote fgsfdsfgs's sdl_input_nx.c from ioquake3-nx to reference current HID refactor names, therefore enabling basic gyro support. (albeit technically incomplete due to no automatic switching of yaw axis to yaw/roll between controllers.)

Gyro can be enabled from the control settings in the main menu. The stock gyro configuration is meant for handheld use, so if you're using a pro/wireless controller you'll have to type "/in_gyromouse_yaw_axis 1" into the console (and if you want to go back to handheld type the last command with a 0 instead of 1). Gyro speed can be adjusted by adjusting the mouse speed.