Filter artefacts using scopes

Rather than calling Mongoid's criteria methods in the controller, call
the scopes from Artefact::FilterScopes instead.

This also includes new functional tests which no longer test the
behaviour of the view template.
Cherry pick conflicts:

	app/controllers/artefacts_controller.rb

Remove industry_sector
Artefact list is 11

This needs to cater for ODI specific test behaviour where we create a test user
and an artefact for them for a profile.
Sort artefact array in test before asserting it
Add integration tests for the new filters
Remove industry sector bits
Show the number of matching artefacts in big type

This shows the number of artefacts which match the current search or
filter.
Set up sass-rails for Panopticon

Cherry pick Conflicts:

	Gemfile
Tweak styles for the artefacts layout

- Remove the "Artefacts" header from the page (the number of artefacts
is a better indicator of what the user is viewing).
- Restore the original width of the filters column (span2).
- A few padding and margin tweaks to the filter form.

Cherry pick Conflicts:

	app/views/artefacts/_filters.html.erb

Remove industry sector.
Fix the selected value of filter box when blank

When there's no filter applied, the select box should explicitly mark
the "All" option as "selected".
Add comment about use of all_of Mongoid criteria
Use semantic markup for the artefact count
Add comment about artefact_scope method
Don't apply a filter for an invalid state

This also includes a similar functional test for checking an invalid
kind parameter.
Don't sort an array with a single value in unit tests

My drive-by sorting of arrays was a little over-zealous.
Count of artefacts is 11

ODI specific as a profile artefact is created for the test user.