feat(components): cell editor added to component details

Added a select on focus [Ext.grid.plugin.CellEditing](http://docs.sencha.com/ext/5.0.0/apidocs/#!/api/Ext.grid.plugin.CellEditing-event-validateedit) to *Components > Properties > Value* so the value can be C&P'ed.

Request from Chrome Webstore:
> Andrew Barfield (https://plus.google.com/+AndrewBarfield) - Feb 25, 2014
>
> ...
> 2) Allow us to 'copy to clipboard' via context menu.
> ...
Merge pull request #90 from stoe/feature/components-detail-value-copy

feat(components): cell editor added to component details