uilayout: add version upgrading to remove XUL persist attributes
* so old/removed persist attributes can be properly removed

(integrated from komodo (trunk) change 84494 by toddw)

git-svn-id: http://svn.openkomodo.com/repos/openkomodo/trunk@14305 b87d16e7-d29f-4ee1-b5ec-817d645d335f