Implement further widget primitives like text inputs or checkboxes and
support custom validation callback functions when instantiating CBI
validators.
Also add support initializing ui.js widgets from the "data-ui-widget"
HTML attribute.
Signed-off-by: Jo-Philipp Wich <jo@mein.io>
Use the new class loader infrastructure to move gui specific
functionality out of the luci.js core and dispatch a new event
'luci-loaded' which is fired once all external classes have
been fetched.
Signed-off-by: Jo-Philipp Wich <jo@mein.io>
