Bump version number to 0.6.0
Add spine-couch-changes adapter to all Spine models
Remove the old/outdated content import functionality from forms
Switch .modelname for .type in spine-couch-changes to match our schema
Rearrange nav menu items
Hide delete button if record has no `id` property yet (not `_id`)

This is so the couchdb _changes feed can work correctly.
Update HISTORY log
Merge branch 'release/0.6.0' into develop