Add const to all project descriptor definitions for safety.

Documentation improvements - put driver example code into its own section, fix incorrect and missing section names.

Make a new general RingBuffer.h misc library driver, instead of the per-application LightweightRingBuff.h ring buffers. Change over projects to use the new driver.

Add ORDERED_EP_CONFIG to the device Projects (only) that use only a single class driver, or where the endpoint ordering is fixed, to save on compiled binary size.

Added new GCC_FORCE_POINTER_ACCESS() macro to correct GCC's mishandling of struct pointers.

Add DEVICE_STATE_AS_GPIOR=0 compile time option to the library projects, to reduce compiled binary size.