Simplify App store charts

Removes the "Advisory rating" chart, and the line chart of apps over
time. Squashes all other charts onto a single line, so they are all
on screen on initial load.
Remove manual margins from examples
Add custom margins back to correlation example
Merge pull request #182 from matthewdunsdon/gh-pages-dev

Remove manual margins from examples on website
Merge pull request #180 from niksoper/gh-pages-dev

Reverted crossfilter.min.js to version 1.3.7
Merge 'upstream' into gh-pages-dev

Conflicts:
	js/controllers/indexController.js
	js/insightChartsControllers.js
Tidy up front-page examples

Adds titles to each chart, and formats the App price to use currency
tick format.

Imports the fix to allow axis line width/color to be changed.
Import title fix

Brings in the fix for title styling, and title padding.
Merge pull request #181 from tpkelly/gh-pages-dev

Simplify App store charts
Imported insight library including manual filtering.
Styled links to show interesting filtering.
Added filtering examples
Moved button to clear filters
Updated filter example links
Allowing filtering to be reset after a chart has been clicked

Imported the updated library including ChartGroup.filterChanged.
Allowing more than one genre or language to be programatically filtered at once.
Using the escape key to clear filters
Styled button for clearing filters