Remove "lazy=joined" from the resource_data backref

This is having some weird interaction with the rsrc_metadata column.
In a later patch I add a call to resource_data_set() in signal_responder
and the metadata tests start failing.

Change-Id: Ib59972fe69570f4ae36e672987419f4841a2de40
Store the generated signed urls in resource_data

This is so it does get regenerated everytime GetRefId() is called.

fixes bug 1206505
Change-Id: Ia69d6d65247555918850ecaadfd1c5d1bc837af8
Merge "Remove "lazy=joined" from the resource_data backref"
Merge "Store the generated signed urls in resource_data"