PLXSW-SIO4 Update 1.2

This update to the PLXSW-SIO4 driver updates the following isues:

1. Fixed DMA operations not working on SIO4B family of card
2. Fixed inability to get same interrupt multiple times in a row

To use this update, simply replace the files "SIO4 Driver C.dll" and
"SIO4 Driver C.lib" in your application directory and rebuild your
application with the new "SIO4 Driver C.lib" file.

