Fix a lot of problems in the parse function

Since it's confusing dealing with both `advanced` and... let's say `traditional` links, I've split the handling of each into separate functions. Also there's a lot of other little changes. 
This line produces 404
Create a multilingual env
Create a category menu in english with alias faulty
Create in the second language a category menu with alias test
Create another category menu with alias faulty and with parent the menu with alias test
try to access faulty in english and in the other language 
get a nice 404 error on the other language