add print-intent snippet to analytics and a shim to support it
appease the linter
refactor to use trycatcher (for now) and move shim to lib
ensure we do not send multiple events in chrome
remove controvesial exception handling, shim and console logs
Merge pull request #409 from alphagov/headless-js-ci

Update jasmine to 2.0.2
Merge pull request #410 from alphagov/repair-js-unit-tests

Repair js unit tests
Configure branch builds
Merge pull request #413 from alphagov/build_branches

Configure branch builds
add print-inetnt to js/analytics asset pipeline
Merge pull request #336 from alphagov/print_intent

Print intent
Added contentSeenTracker script

This script looks for elements with the attribute 'data-track-seen' and
sends an analytics event when the user scrolls the page to show that element.

An addition will be made to govspeak to allow editors to add these tracker
tags to content.
Refactored ContentSeenTracker into constructor pattern
Tracker uses class/id instead of data-track-seen

Govspeak permits classes and ids on permitted html elements. Using them
for tracking means we don't have to make any changes to govspeak.