Revert "Try to stop user from tabbing outside of open dialog box"
Revert "Try to stop user from tabbing outside of open dialog box"

Turns out :focusable is a jQuery UI feature.

This reverts commit 3232d6fa6eafe2ee84a9e095f59a394b8d3ac911.

Change-Id: I72724a6df8d3df6dfe6e98da5f010fc563a362d8

wikimedia/oojs-ui,wikimedia/oojs-ui,wikimedia/oojs-ui,wikimedia/oojs-ui