Having PCM as a singleton is a problem, as multiple things need to use it, and that gets really ugly. This changes PCM's to be a reference counted object, that can be passed around and constructed from multiple places.
In Java, this is using a map to hold a data store with a ref count, and allocating new objects any time a duplicate is requested.
In C++, this uses a trick constructor to store a PCM instance in the data store itself. This instance can then be passed to base objects using std::shared_ptr's aliasing constructor, which means constructing a solenoid from a PCM is not allocating after the 1st one.
This did require removing sendable from PCM. A compressor class was added back in to act as sendable for the PCM.
After this change is finished, the only change RobotBuilder and Team Code would require is passing a module type to solenoid constructors.
Co-authored-by: sciencewhiz <sciencewhiz@users.noreply.github.com>
The old headers were moved into folders because doing so avoids polluting
the system include directories.
Folder names were also normalized to lowercase.
Instead of defining NAMESPACED_WPILIB to remove the "using namespace frc"
shim in Base.h, instead require NO_NAMESPACED_WPILIB be defined to add it.
Fix up various examples to use correct namespacing.
