[2/2] spark git commit: [SPARK-4525] Mesos should decline unused offers

[SPARK-4525] Mesos should decline unused offers Functionally, this is just a small change on top of #3393 (by jongyoul). The issue being addressed is discussed in the comments there. I have not yet added a test for the bug there. I will add one shortly. I've also done some minor

[2/2] spark git commit: [SPARK-4525] Mesos should decline unused offers

[SPARK-4525] Mesos should decline unused offers Functionally, this is just a small change on top of #3393 (by jongyoul). The issue being addressed is discussed in the comments there. I have not yet added a test for the bug there. I will add one shortly. I've also done some minor