* Reworked some of the transfer handling after reading the specs.
* Ensure that the device selection bit is set correctly for all commands.
* Generally disable interrupts and enable them only when expecting a DMA one.
* Renamed disk failure to device fault according to specs.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@30248 a95241bf-73f2-0310-859d-f6bbb57e9c96