Fixed: parentSelector is now a selector rather than a jQuery object

Closes #238
WIP: updating how link box displays

-Explicitly declared font size in link popup

-Width changed to em and added to input object; popup wrapper now has automatic size to include all of input

-Padding/"external" dimensions for input moved to popup wrapper and changed to em values

Refs #226
WIP/not closing issue as I'm not sure this works in every case. Waiting for Fogarty or Evan to test it.