Version bump for JS tracker.
Added TODO list
Fixed document reference to use documentAlias (#247)
Added test of setCustomUrl
Fixed bug with setCustomUrl - #267
Actually setCustomUrl was working - the problem was that the
url being passed to collector was not being set from currentUrl.
Changed ev_ to se_ for structured events (#197)
Tidied up event names passed into getRequest
Clarified unsure when this version will be released
Updated CHANGELOG
Merge branch 'master' into feature/js-improve

Conflicts:
	CHANGELOG
Fixed
Added git submodule link for Snowplow Lua Tracker (#292)
292 now done
Fixed Firefox security errors with sessionStorage and localStorage (#163)
Fixed page ping bug where pageXOffset and pageYOffset were incorrectly being used directly (#260)
Replaced forEach as not supported in IE 6-8 (#295)
Bumped to 0.12.0
Fixed on today's date