Add .ruby-version to 1.9.3

We don't actually execute any Ruby in this project, except for during
the build process.

I think this will alleviate some issues when installing gems:

    sudo: no tty present and no askpass program specified
    Sorry, try again.

    Gem::Exception: Cannot load gem at [/var/lib/gems/1.9.1/cache/sass-3.2.12.gem]
Use bundle exec when building Sass in production

So that we use the copy of the sass binary in vendor/cache.
Check in first version of monthly-by-lot timeseries graph
Use only one year's data in Backdrop stub, like live query
Add basic test for g-cloud by-lot graph
Fix neg number bug in roundToSignificantFigures

And make it a method on View.
Move rounding changes tests into correct place

And remove one duplicate.

And tidy whitespace on an object, remove unused thresholds (they're
duplicated below).
Change rounding thresholds from 500 to 1000

For all orders of magnitude.

I think there's an opportunity for some refactoring here.
Fix asset digest in development

I broke Sass compilation in development. Sorry.

Currently, development will use a cachebusted URL for CSS. However
when you make a change to a Sass file, Sass will only create a file
called spotlight.css which means you won't see the changes you've
just made (as your view is still using the old cachebusted file).

This change means that in development, the asset digest is still
used but the cachebusted filename is equal to the non-cachebusted
filename. So you can go and edit Sass files to your heart's content
and see the changes without restarting the server.

Happy New Year! :fireworks:
Revert "Add basic test for g-cloud by-lot graph"

This reverts commit da36401ba6f290706956827ff0a9cea4830f5a03.
Merge pull request #116 from alphagov/g-cloud-by-lot

Add "spend by lot" grouped timeseries graph to G-Cloud dashboard
Merge pull request #120 from alphagov/fix-asset-digest-dev

Fix asset digest in development
Make module_actions JavaScript more reusable

Rename module_actions to popover (à la iOS) so that we can use it
for a dashboard's related links. Include a basic first pass of
popover in related_pages.
Move popover related Sass into a single file

Use mixins to include it in multiple places.
Reorganise index.scss into logical groups

Also rename module_actions to module_more_info for ease of scanning.
Merge pull request #115 from alphagov/62545960-hide-related-links-small-screens

Hide related links on small screens
Show quarterly ticks on x-axis for monthly data over long timeframe.

When we have monthly data going back more than 15 months, use quarterly ticks.

I've over-written the "month" config in graph.js. We don't seem to be using
this anywhere in the live app, or testing it, so I think it's OK to overwrite.
But I'd be grateful if someone with more Spotlight experience could check.
Add currency symbols to graph.

Committing on a clean branch, this supersedes the previous branch.

Part of the G-Cloud story: https://www.pivotaltracker.com/s/projects/911874/stories/62377934

Provide a configurable "currency" option in Stagecraft. If set, use currency symbols in y-axis labels and callouts.

Allow both for currency prefixes (like "£10") and possible future suffixes (like "10 CNY").

If the currency option is set, use one fewer decimal place in the numbers shown in callouts, so that the text does not overflow as a result of having an extra character. This doesn't account for the possible future use of suffixes, but I suggest we look at that when we get there.
Use "gcloud" rather than "g-cloud" in Stagecraft stubs, to match Backdrop URLs
Ensure configurable "period" property is passed to Backdrop: update tests