Introduces a new path parser that uses the : token to represent a variable. It isn't fully featured but is just capable enough to work for ratFE FossilOrigin-Name: f7646dd5278f3c509d96307e45dc216522f81d9b93eb6b17125dc1b1892b1eee
FossilOrigin-Name: ac401de0a31c87a9c1f72bbf3af3ad385d93729b60b63e37315ee1797a7c91b0