[Spark-1134] only call ipython if no arguments are given; remove IPYTHONOPTS from call

see comments on Pull Request https://github.com/apache/spark/pull/38
(i couldn't figure out how to modify an existing pull request, so I'm hoping I can withdraw that one and replace it with this one.)

Author: Diana Carroll <dcarroll@cloudera.com>

Closes #227 from dianacarroll/spark-1134 and squashes the following commits:

ffe47f2 [Diana Carroll] [spark-1134] remove ipythonopts from ipython command
b673bf7 [Diana Carroll] Merge branch 'master' of github.com:apache/spark
0309cf9 [Diana Carroll] SPARK-1134 bug with ipython prevents non-interactive use with spark; only call ipython if no command line arguments were supplied

bin/pyspark

@@ -55,8 +55,9 @@ if [ -n "$IPYTHON_OPTS" ]; then
   IPYTHON=1
 fi
 
-if [[ "$IPYTHON" = "1" ]] ; then
-  exec ipython $IPYTHON_OPTS
+# Only use ipython if no command line arguments were provided [SPARK-1134]
+if [[ "$IPYTHON" = "1" && $# = 0 ]] ; then
+  exec ipython 
 else
   exec "$PYSPARK_PYTHON" "$@"
 fi