Example encoding and decoding using SD erasure codes. This is code to accompany the ACM Transactions on Storage paper entitled "Sector-Disk (SD) Erasure Codes for Mixed Failure Modes in RAID Systems" by James S. Plank and Mario Blaum. This paper is set to appear in 2013. The precursor paper is "SD Codes: Erasure Codes Designed for How Storage Systems Really Fail", by James S. Plank, Mario Blaum and James L. Hafner, which appeared in Usenix FAST 2013: http://web.eecs.utk.edu/~plank/plank/papers/FAST-2013-SD.html