Arduino 1.0 SD Library ported to chipkit 0023
Only tested with mpide-0023-windows-20120903 release
multiple files (2 tested) open at one time
subfolders report their contents reliably (read, exist, remove tested)
Merge pull request #333 from mskoczen/sd1.0-0023

Arduino 1.0 SD Library ported to chipkit 0023