Offer easy download of browse/search results or a single calibration

[jimallman]

Once we have a uniform API that separates result data from presentation, it should be pretty easy to add a Download This button to a few pages in the FCD website:

• search results
• browse results?
• single calibration page

This would simply download the raw data for a calibration, or a list of calibrations, in a chosen format (JSON or CSV).