Make README visually more appealing on Github with Markdown.


git-svn-id: http://dev.piwik.org/svn/trunk@7837 59fd770c-687e-43c8-a1e3-f5a4ff64c105
Make travis.sh executable

refs #3722


git-svn-id: http://dev.piwik.org/svn/trunk@7838 59fd770c-687e-43c8-a1e3-f5a4ff64c105
Refs #3619, several improvements/modifications to Referrers overview, including:

* Add Total referrer metrics to evolution graph which are always displayed.
* Added evolution percentage next to sparklines.
* Moved other sparklines (for distinct metrics) to smaller section that slides down.

Notes:
* Fixed bug in broadcast.js where '+' chars were removed when sanitizing query params.
* Moved multisites evolution & previous period calculating code to Piwik core.
* Added section-toggler-link code to common js code (CoreHome/misc.js).
* Refactored evolution percentage code used for row evolution popup.



git-svn-id: http://dev.piwik.org/svn/trunk@7839 59fd770c-687e-43c8-a1e3-f5a4ff64c105