Updated SGD parser to use new Bio2RDF API/Release 3 guidelines
Release 3 updates to sgd/sgd.php:
Fixing conflict for release 3 affymetrix
deleted affymetrix
Re-added non-conflicting affymetrix.php
Merge pull request #237 from alisoncallahan/sgd-release3

Sgd release3
Deleting conflicting SGD