Avoid warning message about invalid refuse_seconds value in Mesos >=0…

….21...

Starting with version 0.21.0, Apache Mesos is very noisy if the filter parameter refuse_seconds is set to an invalid value like `-1`.
I have seen systems with millions of log lines like
```
W0420 18:00:48.773059 32352 hierarchical_allocator_process.hpp:589] Using the default value of 'refuse_seconds' to create the refused resources filter because the input value is negative
```
in the Mesos master INFO and WARNING log files.
Therefore the CoarseMesosSchedulerBackend should set the default value for refuse seconds (i.e. 5 seconds) directly.
This is no problem for the fine-grained MesosSchedulerBackend, as it uses the value 1 second for this parameter.

Author: mweindel <m.weindel@usu-software.de>

Closes #5597 from MartinWeindel/master and squashes the following commits:

2f99ffd [mweindel] Avoid warning message about invalid refuse_seconds value in Mesos >=0.21.

core/src/main/scala/org/apache/spark/scheduler/cluster/mesos/CoarseMesosSchedulerBackend.scala

@@ -207,7 +207,7 @@ private[spark] class CoarseMesosSchedulerBackend(
    */
   override def resourceOffers(d: SchedulerDriver, offers: JList[Offer]) {
     synchronized {
-      val filters = Filters.newBuilder().setRefuseSeconds(-1).build()
+      val filters = Filters.newBuilder().setRefuseSeconds(5).build()
 
       for (offer <- offers) {
         val slaveId = offer.getSlaveId.toString