Test that shows multiple instances watching the same file doesnt work. Ref GH-31.
Make the multipleWatchers test time out after 1s.
Allow multiple instances polling the same file.

Fixes shama/gaze#31, yeoman/grunt-regarde#7.

Problem: Different instances would call `fs.unwatchFile` (in `Gaze.close`)
when initializing without passing the listener, thus causing node to
unregister *all* callbacks that were registered for the given file.

Solution: Remeber the callback, that was passed when calling
`fs.watchFile` and use that for "unregistering" with `fs.unwatchFile`.
Rename _this to self as its cleaner looking.
Move helpers to their own file
Fix node 0.10 path.resolve errors.
Update docs, no longer supports node v0.6
Update travis to node 0.10
Fix lint errors
Remove node 0.6 stuff
Register new files when added to new directory. Fixes GH-14.
Remove unused dep
Quote node 0.10
Patch bad rebase