Merge pull request #731 from pxinghao/master

...ain/scala/spark/mllib/classification/Classification.scala

...scala/spark/mllib/classification/LogisticRegression.scala

mllib/src/main/scala/spark/mllib/classification/SVM.scala

mllib/src/main/scala/spark/mllib/optimization/Gradient.scala

...main/scala/spark/mllib/optimization/GradientDescent.scala

mllib/src/main/scala/spark/mllib/optimization/Updater.scala

mllib/src/main/scala/spark/mllib/regression/Lasso.scala

.../src/main/scala/spark/mllib/util/LassoDataGenerator.scala

mllib/src/main/scala/spark/mllib/util/SVMDataGenerator.scala

.../spark/mllib/classification/LogisticRegressionSuite.scala

.../src/test/scala/spark/mllib/classification/SVMSuite.scala

mllib/src/test/scala/spark/mllib/regression/LassoSuite.scala