Record timezone audio recordings and audio events were created.

[cofiem]

Right now this information has to be inferred from the site location, which is difficult (and not required to be present). Changing this also affects #22 #24.

[atruskie]

We have a pending repair of our audio data (maintenance and the like) where we plan to normalize the timeformat used in the original audio file names (currently some are still in +10, we want them all in UTC). I think during that process might be the time to address this issue.

Also audio_events? Creation date is not so important is it?
Absolute start date can be inferred from the relation to audio_recordings...

[atruskie]

This change will require a db/schema modification - that is proactively added by the harvester.

[cofiem]

Comments continued at pull request: #121

[cofiem]

Added in f19d90e:

• Ability to store timezones for site & users
• UTC offset for audio recordings

UTC offset for audio recording is not yet stored by harvester.