[ 926123 ] Rewrote AbGetDriveFreeSpace to always use GetDiskFreeSpaceEx on Windows and fixed it to return correct values larger than MaxInt.  Simplified Linux side as well.
[ 926123 ] Rewrote AbGetDriveFreeSpace to always use GetDiskFreeSpaceEx on Windows and fixed it to return correct values larger than MaxInt.  Simplified Linux side as well.

rburgstaler/tpabbrevia,rburgstaler/tpabbrevia,rburgstaler/tpabbrevia,rburgstaler/tpabbrevia,rburgstaler/tpabbrevia,rburgstaler/tpabbrevia