Tour Audio - Part 1

Can now add and preview audio to tours (by linking to an MP3 audio
file.) Part 2 (not in original requirements but obviously required) is
to provide tour step timings (in seconds) so steps in the tour can be
synchronized with the audio.
Tour Audio - Part 2

Implemented tour step lapsed timings UI, so each tour step can be
displayed at a specified point in the audio track, which is measured in
seconds.
Tour Audio - Firefox Fix

Fixes position of tour stop inputs for Firefox. (Was not an issue in IE,
Chrome, Webkit...) Firefox position was floating to the right.
JS and CSS Versioning

Fixed choices of files used to get timestamp.
Merge branch 'NeilCresswell-tour-audio'