Fixes #397 by @ryssbowh and @kostajh: Improved sanitization

I went ahead and squashed this into a single commit. Thanks to
both of you for your work on it.

There is still work to be done:
- ->data still has lots of stuff in it
- Actual location lat/lon is there.

I think this is a huge improvement.
Merge branch 'site' of https://github.com/warmshowers/Warmshowers.org into site