Update some Kconfig comments; Add a upper limit on the lower priority worker thread for priority inheritance

Remove non-functional vestiges of OTGHS in FS mode (including OTGFS2); try to convert the stm32f429i-disco configuration to use OTGHS instead of OTFHS in FS mode (OTGFS2).  But I don't have the boards and can't test

Integrates OTGHS support into the STM32; Eliminates the older OTGHS in FS mode logic.  From Brennan Ashton

Add files that implement true high speed support for the STM32 OTGHS peripheral.  From Brennan Ashton

The Asynch I/O implementation now satisfies POSIX priority requirements; it uses the new low priority worker thread interfaces to adjust the priority of the worker thread according to the priority of the client thread

Fix a place in the memory manager where it explicitly assumes that the size of a point is 4 bytes.  That is OK if the actually size is smaller but makes the heap unstable when used withthe x86_64 host simulation

Major structure of file system functions to better support asynchronous I/O.  Respository should not be trusted until I have a chance to verify everything