Initial impl of named routes

* introduced named routes
* introduced UrlPattern interface
* implemented UrlTemplate
* removed handlers
Minor cleanup.
_go tests to call mock history/location
Implemented go(replace: true)
more tests for for hierarchical routes
minor renaming
Added remove route and fixed route reversal
Working on a nicer example
added .buildlog git ignore
Route should be re-entered if route params change
deleted out folder
ignoring out folder
Extending/fixing the example
Removing all the mutation apis
Split everything into Route and Router
Completed the example
Cleanup
Added some loading indicators
Even better loading indicator.
full example: root-view cleanup