[SPARK-6435] spark-shell --jars option does not add all jars to classpath

Modified to accept double-quotated args properly in spark-shell.cmd.

Author: Masayoshi TSUZUKI <tsudukim@oss.nttdata.co.jp>

Closes #5227 from tsudukim/feature/SPARK-6435-2 and squashes the following commits:

ac55787 [Masayoshi TSUZUKI] removed unnecessary argument.
60789a7 [Masayoshi TSUZUKI] Merge branch 'master' of https://github.com/apache/spark into feature/SPARK-6435-2
1fee420 [Masayoshi TSUZUKI] fixed test code for escaping '='.
0d4dc41 [Masayoshi TSUZUKI] - escaped comman and semicolon in CommandBuilderUtils.java - added random string to the temporary filename - double-quotation followed by `cmd /c` did not worked properly - no need to escape `=` by `^` - if double-quoted string ended with `\` like classpath, the last `\` is parsed as the escape charactor and the closing `"` didn't work properly
2a332e5 [Masayoshi TSUZUKI] Merge branch 'master' into feature/SPARK-6435-2
04f4291 [Masayoshi TSUZUKI] [SPARK-6435] spark-shell --jars option does not add all jars to classpath