fix bug 829765 - Redirect apps landing to apps wiki page *DO NOT MERGE*

*DO NOT MERGE*

This removes the apps landing page, allowing redirection to the Wiki document, as specified in ticket 829765 (https://bugzilla.mozilla.org/show_bug.cgi?id=829765).  

It wasn't until after I completed this that I discovered merging this will rely on closing (https://bugzilla.mozilla.org/show_bug.cgi?id=829756) first.