Existing Things have both links and forms after upgrade

[benfrancis]

STR:

• Install 1.1
• Add a Zigbee device
• Upgrade to 1.2.0-alpha.1
• Fetch Thing Descriptions from /things using Accept: application/json header

Expected:

• Things have forms instead of links in their Thing Descriptions

Actual:

• Things do have forms, but they also still have top level links for properties, actions and events, and empty links arrays under properties

(Note: Presented with latest master of zigbee add-on)

[benfrancis]

Also reproduces with Virtual Things adapter so probably happens to all adapter add-ons.