Allow configurable image path

Use the file-url function for image paths so that these can be
configured differently on projects that have a different directory
structure.
Merge pull request #46 from p-m-p/master

Allow configurable image path
Remove govuk_template examples

The govuk_template can now be previewed at
http://alphagov.github.io/govuk_template/
Remove duplicate example templates within GOV.UK elements.
Show radio and checkbox toggled content

- Add javascript for radio button and checkbox examples
- Add new checkbox example showing Register to vote - What is your
nationality?
- Update snippets page
- Add new checkbox snippet
Merge pull request #49 from alphagov/add-toggled-content-examples

Examples for radio and checkbox toggled content
Update govuk_frontend_toolkit to 2.0.1

# 2.0.1

- Fix new grid helpers to ensure content using %site-width-container is
centred in IE.

# 2.0.0

- Add support for selection-button events to be document-level
https://github.com/alphagov/govuk_frontend_toolkit/pull/139

- The `GOVUK.selectionButtons` interface is now deprecated. Details are
in the
[README](https://github.com/alphagov/govuk_frontend_toolkit#deprecated-f
unctionality).
Update SelectionButtons to new interface
Fix grid layout examples for IE7 and below

- Reduce the width of example boxes for IE7 and below
- Recalculate widths for grid columns within example boxes
- Scale images to fit grid columns
- Use height rather than min-height to maintain example grid height
Set a colour for form labels

This isn’t inherited and is appearing in blue in IE7 and below, set a
colour to fix this.
Fix bulleted lists in IE7 and below

Use padding rather than margin so bullets are visible
Fix numbered lists in IE7 and below

Increase padding for IE7 and below to fix numbers being cut off.
Remove routes for GOV.UK template example pages

The example pages now published here:
http://alphagov.github.io/govuk_template/
The routes should have been removed as part of 8e5f37.
Fix details summary polyfill

This was causing an error in IE7 and below.
Fix rendering of down arrow for details polyfill

Setting the font-style to normal overrides font-style:italic, which is
applied by the browser to the
<i> element used for icons. This fixes the appearance of the down arrow.
Bump govuk_frontend_toolkit to 3.0.1

- Update gruntfile.js copy paths since the front end toolkit is no
longer nested inside a folder of the same name
- Fix typo in _grid_layout.scss
Bump govuk_template to 0.10.1

- Force the scrollbar to always display in IE10/11
- Add font-smoothing for Firefox
- Update favicon
Fix unwanted button padding in Firefox

Buttons are slightly larger in Firefox than in Chrome, this fixes that
issue.
Use tablular numbers for tables

- Set table cells to use tabular numbers
- Ensure spacing is 15px above and below table content
- Set px to em function to use 16px as a base to generate em values,
(as we’re using the core-16 mixin), otherwise this defaults to 19px.
Create examples for right-aligned table cells

- Add numerical table cell example with right-aligned numbers
- Update table example to compare left-aligned text
- Update guidance for right-aligned table cells and link to tabular
numbers
Add left-aligned table example