add all categories functionality

user can now click "All" in the categories list to view all
recipes; just in case they filtered by categories and want to
go back
remove signals for category on click and all

the signals will be handled in categorylist

this makes sense because the browse controller
has categorylist anyway.
remove debug outputs
removed debug output for filterByCategory
add switch from categoryPage to recipesPage

* can also go back to categoryPage
* need to make recipesPage remember current item selected