Add 'Scheduling Tasks with Bukkit'

Add 'Scheduling Tasks with Bukkit', a tutorial post explaining how to
successfully implement recurring tasks in a bukkit plugin.
Fix grammar issue in scheduling-tasks-with-bukkit

Remove the word 'the' on line 49 of
2014-05-07-scheduling-tasks-with-bukkit.md, as it isn't needed.
Merge remote-tracking branch 'origin/scheduling-with-bukkit'