Cleanup: coding style fixes
Plain DOM objects work fine
Cleanup: simplified function calls
MT: It's enough to only focus the area once
MT: be more explicit when returning data to the callback
Cleanup: moved var declarations to the top
Cleanup: readability improvements
Cleanup: removed dead variable

No value other than undefined is returned, there's no sense on keeping
this around.
MT: trigger input event when updating textarea values
MT: simplified selector