Update WPILib, roborio compilers, and CTRE Phoenix libraries

This borrows heavily from work that Ravago did to initially get this
stuff working.

Tested rudimentary functionality on a test bench, ensured that we could:
* Enable the robot.
* Read joystick and button values.
* Switch between auto and teleop modes.
* Read sensor values (encoder, absolute encoder, potentiometer).
* Read PDP values.
* Drive PWM motors.
* Drive CANivore motors.

Non-WPILib changes are made to accommodate the upgrade roborio
compiler's improved pickiness.

Merge commit '125aac16d9bf03c833ffa18de2f113a33758a4b8' into HEAD

Change-Id: I8648956fb7517b2d784bf58e0a236742af7a306a
Signed-off-by: James Kuszmaul <jabukuszmaul+collab@gmail.com>
diff --git a/third_party/rawrtc/usrsctp/BUILD b/third_party/rawrtc/usrsctp/BUILD
index 4c9c015..6d1fa69 100644
--- a/third_party/rawrtc/usrsctp/BUILD
+++ b/third_party/rawrtc/usrsctp/BUILD
@@ -53,6 +53,7 @@
         ],
         "gcc": [
             "-Wno-discarded-qualifiers",
+            "-Wno-maybe-uninitialized",
         ],
     }),
     includes = [