Checkpoint commit with a list of acceptance filters - need to change.
Another checkpoint going a static array...still need to change again.
Move to a simple list of accep. filters - handle tables in platforms.
Standardize add/remove filter functions, re-configure on all platforms.
Merge branch 'next' into filter-refactor

Conflicts:
	src/platform/pic32/canutil.cpp
Add buses array to filter initialization functions.
Load AF entires one by one, since it's easier than sorting the table.
Minimize the number of places where AF mode changes.
Manually zero out the CAN AF register, the NXP library is buggy.

The previously method left the AF table corrupted and no filters would
work.
Update PIC32 CAN AF initialization to match LPC17xx - not working yet.
Fix new acceptance filter setup in PIC32 - disable before changing.
Patch up a test case for the new CAN filter API.