Add CAN bit timing values for use with 120 MHz and 96 MHz system clocks.

The values used produce sampling points around 65-70% which is similar
to the original set of values.

Values courtesy of http://www.bittiming.can-wiki.info/
Merge pull request #40 from smartavionics/mb-stm32f4-can-timing

Add CAN bit timing values for use with 120 MHz and 96 MHz system clocks.
Merge pull request #39 from smartavionics/mb-misc-mods

Mb misc mods
Merge pull request #42 from smartavionics/mb-misc-mods

Change a couple of #warn directives to #warning.
For STM32, use CAN_NO_MB instead of CAN_TxStatus_NoMailBox.