Merge pull request #262 from jhgg/master

Fix bug where hydra.exec would throw an error if command returns nothing
Started changing event handlers (part of #241).
Converted pathwatcher to C, as part of #241.
Simplifying internal mass handler removal API, part of #241.
Using internal handler API for applistener; part of #241.
Fixed applistener.stopall; part of #241.
Changed the timer module's internals; part of #241.
Removed NSLog (oops)
Deleted applistener.lua; closes #241.
Temporarily deleting eventtap code for a little bit.
Renaming audio -> audiodevice.
Renaming a class for some reason.
Moved applistener -> notify.applistener, as part of #254.