Start using admin gem

* Add govuk_admin_template
* Remove jquery-rails, jQuery is provided via gem
* Upgrade jquery-ui, formtastic, formtastic-bootstrap
Switch to using govuk_admin_template layout

* Use nested layouts
* Import gem’s SASS styles
* Remove now unnecessary javascript and SASS includes
* Remove HTML5 shim, now provided by gem
* Remove theme bootstrap overrides
* Update style of jquery-ui include to match newer gem
Include admin template style guide

* Keep a reference to admin design patterns
* Show how local styles may have affected those patterns
Update filter form to Bootstrap 3

* Remove custom styling
* Remove old Bootstrap grid classes, form elements now expand to width
of container
* Add Bootstrap 3 form classes
Update Whitehall artefact form to Bootstrap 3

* Replace old grid classes with gem’s input helpers
* Remove row wrappers
Update Bootstrap grid classes

* Replace row-fluid with row
* Update span classes to col-md classes
* Update span classes on inputs to use gem input-md helper classes
* Remove wrapping rows and span12 classes where unnecessary
  * Form elements expand to full width by default now
* http://getbootstrap.com/css/#grid
Switch to Bootstrap 3 glyphicons

* Replace `icon` with `glyphicon`
* No need to specify icon colour, Bootstrap 3 icons are font based and
inherit the text’s colour
Buttons need a default class in Bootstrap 3
Give artefacts table header contrast

* Bring table inline with admin style guide
Use bootstrap 3 kaminari themes for pagination

* Pull themes from gem:
https://github.com/matenia/bootstrap-kaminari-views
Update flash message classes

* Default notice and alert message types to the bootstrap “warning”
alert
* Be explicit about success messages, and show them in green
* Stop sliding up flash notices
* Remove overrides that made warnings green
Cleanup artefacts count

* Give filter column more space
* Use number with delimiter
* Use big number styles from gem
* Remove bespoke artefact count styles
Cleanup tag fields in artefact forms

* Add missing form-control class
* Use helper class for vertical margins
* Remove bespoke styles
* Position remove button absolutely rather than with floats
Cleanup curated artefacts list

* Apply same changes as tag fields
* Make remove buttons absolute
* Add missing form classes
* Icons can now use text colour rather than opacity
Cleanup tag index

* Reset list styles using Bootstrap helper class
* Mute secondary links
Fix display of slug in new tag form

* Use form_control_input_html_options so text input has correct
bootstrap classes
* Rather than generating HTML to prepend, use the built-in prepend
method, and merge this with existing input options. See:
https://github.com/justinfrench/formtastic#creating-new-inputs-based-on-
existing-ones
Add spacing beneath artefact tabs

The well and the tabs were too close together.
Upgrade chosen js library to 1.1.0

* Also modify old chzn classes
Style chosen selects to match Bootstrap 3

* Pulled from:
https://github.com/alphagov/signonotron2/commit/e1610da934af53b4734b56e6
f3a7180a55b4ae49
Remove bootstrap overrides and old assets

* Custom overrides of Bootstrap 2 styles no longer needed
* Delete old header styles
* Delete crown asset