init
Tag and untag done by extending jQuery
To be done next:
1, keyboard control
2, split word
3, merge word
dropdown-menu loaded on the fly added
split word backend done
split word front end done, linking the backend and frontend to be done
working on keyboard navigation
keynav(single row) done
Separate tagging utility to another file.

Besides, modulize tagging into basic tagging function and keyboard operation.

I think it is much better now!
keyboard split partially done(keynav within splitted chars, disable ingredient keynav when splitting
nested keynav in progress
keynav infrastructure built, key-based split word done. cool
merge work in progress
keynav + splitword improved, cleaner code\!