Detail:
  * No longer uses temporay HAL DMA entry points, all hardware access is
    accomplished using device entry points.
  * Supports multiple DMA controllers, including dynamic addition and
    removal of controllers (using OS_Hardware 4 and Service_Hardware).
  * Added *DMAChannels, which enumerates the currently registered DMA
    channels, listed according to physical location.
  * Logical channel blocks are dynamically allocated (as a requirement of
    the above changes) so logical channel handles are now pointers, no
    longer an array index. Just so you know.
  * Removed now-obsolete EnumerateLogical entry from controller device API.
  * Added pointer-to-controller-device item in publically visible part of
    channel device structure.
  * Moved memory-to-memory channel device entries to end of channel device
    structure (I'm considering removing them).
  * Added support for GPA debugging listing (requires BuildSys 3.86).
Admin:
  Tested on Tungsten (ie floppies still work).

Version 0.15, 4.4.2.6. Tagged as 'DMA-0_15-4_4_2_6'