[WIP] bootstrapify

use bootstrap for menubar, dialogs and basic layout

removes our custom shipped jquery-ui checkpoint, as we no longer need a non-standard version,
and can fallback on the stable release in `components`.

Requires ipython/ipython-components#3

This does not reach into the notebook cell layout at all.

Still some wonkiness to work out, but it's previewable now, I think.

things I know need fixing:

- [x] raw input broken
- [x] can't delete notebook in dashboard
- [x] header alignment
- [x] cell toolbar
- [x] layout app_height is off (pager handle is pushed off the screen)
- [x] top of the header sometimes sits outside the page
- [x] cell type selector empty when value is 'code'
- [ ] click events a little weird in the menu if no action is ultimately taken
- [x] modify url hash when switching tabs in tree view
- [x] de-ui-widget save widget
- [x] de-ui-widget notification widget
- [x] de-ui-widget help keyboard-shortcut
- [x] pager handle full-width
- [x] scrollbar pulled to the edge of the page
- [x] no more white space below the last cell at the bottom of the screenn
- [x] think of positionning / styling "wrong password on login screen" 
- [x] bootstrapify dashboard delete dialog.
- [x] Dashbord, the "container" scoll horizontally 
- [x] Dashbord, center text vertically in each row.
- [x] Breadcrumb css weird.