began to merege the SVIGP code into GPy.

Example is implemented, but the step length is a bit crazy!

GPy/models/__init__.py

@@ -4,6 +4,7 @@
 from gp_regression import GPRegression
 from gp_classification import GPClassification
 from sparse_gp_regression import SparseGPRegression
+from svigp_regression import SVIGPRegression
 from sparse_gp_classification import SparseGPClassification
 from fitc_classification import FITCClassification
 from gplvm import GPLVM