Modifications for permissions and method for JS addition

This patch touches on a few different areas and gets a bit meta. Hopefully it also lays a clearer path for additional patches around controlling the addition/exclusion of the JS on the site.

• Implements an admin permission specific to sumome (and uses that permission to control access to the configuration screen).
• Adds a link to the configuration screen to the .info file (so it will be accessible directly from the Modules admin screen).
• Moved the application of the JS from hook_init() to hook_page_build() (per note from here: https://twitter.com/davereid/status/294554866649542657).
• Changed the code injected via drupal_add_html_head() to avoid the weird self-closing SCRIPT tag that needed a suffix for proper closure.