Geokey-export

Fixed radios for selecting expiration of an export.

Fixed retrieving contributions of a category via Ajax endpoint when user is a creator of an export but not an admin of a project anymore.

Fixed zooming in to geography of an export. Also, some fixes and adjustments to better support GeoKey v0.9.2 and greater.

Introducing BOUNDING BOX: now each export can also limit the area of data to be exported.

The extension has been redesign for better access and management.

Fixed bug when export was trying to access a deleted project and crashing. Now when the project is deleted, export gets deleted too.