Rename executeAfter to scheduleTime
Rename DelayedPriorityTaskItemReader to LazyPriorityTaskItemReader
Rename isPast to isReady, timer to clock in DelayedTaskIterator
Add support for delayed tasks in bwl service
Remove previous pre-implementation of delayed tasks in PriorityTaskItemReader
Add support for delayed tasks in LogQueue
Add test for delayed tasks in TestLogQueueFeeder
Fix a NullPointerException due to an incomplete mock
Changes after review

* Expose delay instead of scheduleTime in API
* Expose delayedTasks as an Iterator[Task] in DelayedTaskIterator
* Few renamings
* Run Scalariform
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
Merge pull request #32 from wajam/clement-delayed-tasks

Add support for delayed tasks in LogQueue