More updates to documentation

docs/_layouts/global.html

docs/api.md

docs/contributing-to-spark.md

docs/css/main.css

docs/index.md

docs/scala-programming-guide.md

docs/spark-standalone.md

examples/src/main/scala/spark/examples/BroadcastTest.scala

...src/main/scala/spark/examples/ExceptionHandlingTest.scala

examples/src/main/scala/spark/examples/GroupByTest.scala

...es/src/main/scala/spark/examples/MultiBroadcastTest.scala

...c/main/scala/spark/examples/SimpleSkewedGroupByTest.scala

...les/src/main/scala/spark/examples/SkewedGroupByTest.scala

examples/src/main/scala/spark/examples/SparkALS.scala

examples/src/main/scala/spark/examples/SparkLR.scala

examples/src/main/scala/spark/examples/SparkPi.scala

examples/src/main/scala/spark/examples/SparkTC.scala