Allow specifying access parameters for each form on the custom config page

Access for each form defaults to require the user have the
'Access Custom Config' permission.  If the user doesn't have
access to any of the available forms, access is denied to the
entire page.
Merge pull request #1 from gapple/individual-form-permissions

Allow specifying access parameters for each form on the custom config page
Removed the init hook which ran in the wrong spot during UI install.