Minimal support for JSON objects in Fields.
Started implementing Entry preview view controller.
Bump deployment target to iOS 7.1
Keep path extension when generating cache file names for Assets.
Use cell style Value1 for primitives.
QuickLook previews for Assets.
Added asset thumbnail operation which fetches Assets in background and creates a thumbnail for them.
Implement support for displaying locations inline.
Implement support for proper Asset previews.
Allow changing the table view style for Fields view controller.
Moved preview-specific stuff to its own class, switch to change visualisation of Entries.

Currently, the segmented control to switch is only visible in one mode, pending decision on where to put it.
Do not animate because it looks silly.
New Content Types view controller which uses preview view controller instead of the plain fields view controller.