Redirect /firefox/customize/ to fix bug 979531

Redirect to australis /firefox/desktop/customize/ page
Remove old template, less, js, images, settings, and url
Change url lookups for firefox.customize to firefox.desktop.customize
Merge pull request #1927 from jgmize/redirect-customize

Redirect /firefox/customize/ to fix bug 979531
Fix Bug 979527 - [australis] redirect /firefox/central to a sumo page