Make Asset#user_id bulk-settable
Make Asset#user_id bulk-settable

This is a little dubious, actually, but it's how Mephisto has
historically worked.  Normally, it would be a security hole, but it only
can be used by logged in users.  I'm marking it with a TODO so we can go
back and deal with it later.

technoweenie/mephisto,mephistorb/mephisto,mat/mephisto,mat/mephisto,technoweenie/mephisto,rwdaigle/old.ryandaigle.com,emk/mephisto,jgoggles/mephisto,jgoggles/mephisto,emk/mephisto,rwdaigle/old.ryandaigle.com,mico/Mephisto-fork,mephistorb/mephisto,mico/Mephisto-fork