Fixed Host mode to Device mode UID change not causing a USB Disconnect event when a device was connected.

Changed per-device controller preprocessor checks over to per-device series for better device control.

Fixed error in Endpoint.c using HSOFI rather than SOFI for counting elapsed milliseconds.

Removed new Start of Frame event from the library; performance suffered far too much and it was only useful in one of the standard classes (HID). Altered HID demos to use the previous method of tracking millisecond periods via a hardware timer rather than the SOF events.

Fixed MIDI class driver blocking on unread events to the host.

Commit of new class abstraction APIs for all device demos other than the MIDI demo - not documented yet.

Removed scheduler and memory allocation libraries.

Added new EVENT_USB_StartOfFrame event in the library to indicate the start of each USB frame (when generated).

Removed Tx interrupt from the USBtoSerial demo; now sends characters via polling to ensure more time for the Rx interrupt.

USB_IsConnected is now cleared before the USB_Disconnect() event is fired in response to VBUS being removed.

Minor documentation improvements.

Fixed incorrect ENDPOINT_EPNUM_MASK mask preventing endpoints above EP3 from being selected (thanks to Jonathan Oakley).

Removed STREAM_CALLBACK() macro - callbacks now use regular function definitions to clarify user code.

Removed DESCRIPTOR_COMPARATOR() macro - comparators should now use regular function definitions to clarify user code.

Removed all user pipe/endpoint interrupt APIs, added internal library support for interrupt driven control endpoints when in device mode by defining INTERRUPT_CONTROL_ENDPOINT token and passing it to the compiler via the -D switch.

Move StdRequestType.h, StreamCallbacks.h, USBMode.h from the LowLevel USB driver directory to the HighLevel USB driver directory, where they are more suited.