[SPARK-4372][MLLIB] Make LR and SVM's default parameters consistent in Scala and Python

The current default regParam is 1.0 and regType is claimed to be none in Python (but actually it is l2), while regParam = 0.0 and regType is L2 in Scala. We should make the default values consistent. This PR sets the default regType to L2 and regParam to 0.01. Note that the default regParam value in LIBLINEAR (and hence scikit-learn) is 1.0. However, we use average loss instead of total loss in our formulation. Hence regParam=1.0 is definitely too heavy.

@davies @atalwalkar
Actually, I prefer using `None` here. It is consistent with 1.1 API.