spark git commit: [SPARK-18686][SPARKR][ML] Several cleanup and improvements for spark.logit.

Repository: spark Updated Branches: refs/heads/branch-2.1 3750c6e9b -> 340e9aea4 [SPARK-18686][SPARKR][ML] Several cleanup and improvements for spark.logit. ## What changes were proposed in this pull request? Several cleanup and improvements for ```spark.logit```: * ```summary``` should

spark git commit: [SPARK-18686][SPARKR][ML] Several cleanup and improvements for spark.logit.

Repository: spark Updated Branches: refs/heads/master 5c6bcdbda -> 90b59d1bf [SPARK-18686][SPARKR][ML] Several cleanup and improvements for spark.logit. ## What changes were proposed in this pull request? Several cleanup and improvements for ```spark.logit```: * ```summary``` should return