* Introduce RoutePattern
Introduces RoutePattern - a new parser and representation for routing
templates, defaults, and constraints.
This is a new representation for all of the 'inputs' to routing that is
immutable and captures 'out of line' information for defaults and
constraints.
This will allow us to unify the handling of constraints and values from
attribute style routes and conventional style routes.
-Renamed RouteTemplate -> RoutePattern
-Made immutable
-Added Builder
-Lots of fixes to parser to support new design
There are a few small issues logged for follow-up but this is mostly in
the place I want it design-wise.
Ryan Nowak
Jass Bagga
N. Taylor Mullen