Listen for NOTE_ATTRIB events

Previously a contents-changed event was not firing when a file was
set to be empty.
Only handle attribute events when file is empty
:memo: Tweak comment
Use ^ style dependency for jasmine-tagged
Use NanDisposePersistent
Tweak description
npm ignre more files
Merge pull request #16 from atom/ks-empty-file-event

Listen for NOTE_ATTRIB events