SPARK-1936 Removed author tags and added apache header

Removed author tags and added apache header for these files

spark\repl\src\main\scala\org\apache\spark\repl\SparkExprTyper.scala
spark\repl\src\main\scala\org\apache\spark\repl\SparkILoop.scala
spark\repl\src\main\scala\org\apache\spark\repl\SparkILoopInit.scala
spark\repl\src\main\scala\org\apache\spark\repl\SparkIMain.scala
spark\repl\src\main\scala\org\apache\spark\repl\SparkImports.scala
spark\repl\src\main\scala\org\apache\spark\repl\SparkJLineCompletion.scala
spark\repl\src\main\scala\org\apache\spark\repl\SparkJLineReader.scala
spark\repl\src\main\scala\org\apache\spark\repl\SparkMemberHandlers.scala