Fix SPARK-1629: Spark should inline use of commons-lang `SystemUtils.IS_...

...OS_WINDOWS`

Author: witgo <witgo@qq.com>

Closes #569 from witgo/SPARK-1629 and squashes the following commits:

31520eb [witgo] Merge branch 'master' of https://github.com/apache/spark into SPARK-1629
fcaafd7 [witgo] merge mastet
49e248e [witgo] Fix SPARK-1629: Spark should inline use of commons-lang `SystemUtils.IS_OS_WINDOWS`
(cherry picked from commit 55100daa6509bed851f6932845deffa861fef245)

Signed-off-by: Patrick Wendell <pwendell@gmail.com>