This modifies the mecanum drive, differential drive, speed controller,
and PID controller widgets to only be writeable when .controllable is
set to true.
This makes code easier to read and more consistent between C++ and Java.
Also update clang-format settings to always add a line break (even if no braces are used).
This reuses many pieces of the current simulation GUI. The common pieces have
been refactored into the libglass library.
The libglass library is designed to be usable for other standalone data
visualization applications (e.g. viewing data logs).
The name "glass" comes from "glass cockpit", as the application features
several multi-function displays that can be adjusted to display robot
information as needed.
