The command and shuffleboard integration tests were removed because
their unit tests counterparts already provide adequate coverage. Java
already removed these.
A lot of these are breaking changes. frc::Timer was replaced with the
contents of frc2::Timer. The others were in-place argument changes or
removing deprecated non-unit overloads.
This reverts commit a79faace1b.
This change will be superseded in a non-breaking way by changing to static functions and deprecating GetInstance() entirely.
Improves consistency across all classes.
Affects Preferences, LiveWindow, and CameraServer.
Old commands Scheduler::GetInstance() was not updated as this is already
deprecated.
The old headers were moved into folders because doing so avoids polluting
the system include directories.
Folder names were also normalized to lowercase.
