Merge branch 'master' into clement-delayed-tasks

Conflicts:
	bwl-core/src/main/scala/com/wajam/bwl/Bwl.scala
	bwl-core/src/main/scala/com/wajam/bwl/queue/log/LogQueue.scala
	bwl-core/src/main/scala/com/wajam/bwl/queue/memory/MemoryQueue.scala