Fix some bugs with spaces in directory name.

Any time you use the directory name (`FWDIR`) it needs to be surrounded
in quotes. If you're also using wildcards, you can safely put the quotes
around just `$FWDIR`.

Author: Sarah Gerweck <[email protected]>

Closes apache#1756 from sarahgerweck/folderSpaces and squashes the following commits:

732629d [Sarah Gerweck] Fix some bugs with spaces in directory name.

make-distribution.sh

@@ -168,22 +168,22 @@ mkdir -p "$DISTDIR/lib"
 echo "Spark $VERSION$GITREVSTRING built for Hadoop $SPARK_HADOOP_VERSION" > "$DISTDIR/RELEASE"
 
 # Copy jars
-cp $FWDIR/assembly/target/scala*/*assembly*hadoop*.jar "$DISTDIR/lib/"
-cp $FWDIR/examples/target/scala*/spark-examples*.jar "$DISTDIR/lib/"
+cp "$FWDIR"/assembly/target/scala*/*assembly*hadoop*.jar "$DISTDIR/lib/"
+cp "$FWDIR"/examples/target/scala*/spark-examples*.jar "$DISTDIR/lib/"
 
 # Copy example sources (needed for python and SQL)
 mkdir -p "$DISTDIR/examples/src/main"
-cp -r $FWDIR/examples/src/main "$DISTDIR/examples/src/"
+cp -r "$FWDIR"/examples/src/main "$DISTDIR/examples/src/"
 
 if [ "$SPARK_HIVE" == "true" ]; then
-  cp $FWDIR/lib_managed/jars/datanucleus*.jar "$DISTDIR/lib/"
+  cp "$FWDIR"/lib_managed/jars/datanucleus*.jar "$DISTDIR/lib/"
 fi
 
 # Copy license and ASF files
 cp "$FWDIR/LICENSE" "$DISTDIR"
 cp "$FWDIR/NOTICE" "$DISTDIR"
 
-if [ -e $FWDIR/CHANGES.txt ]; then
+if [ -e "$FWDIR"/CHANGES.txt ]; then
   cp "$FWDIR/CHANGES.txt" "$DISTDIR"
 fi