Passing path parameters with invalid encoding is likely to trigger errors
further on like `ArgumentError (invalid byte sequence in UTF-8)`. This will
result in a 500 error whereas the better error to return is a 400 error which
allows exception notification libraries to filter it out if they wish.

Closes #4450

This fixes the following scenario:

    resources :contacts do
      post 'new', action: 'new', on: :collection, as: :new
    end

Where the /new path is not generated because it's considered a canonical
action, part of the normal resource actions:

    new_contacts POST   /contacts(.:format)          contacts#new

Fixes #2999

A callable object passed as a constraint for a route may access the request
parameters as part of its check. This causes the combined parameters hash
to be cached in the environment hash. If the constraint fails then any subsequent
access of the request parameters will be against that stale hash.

To fix this we delete the cache after every call to `matches?`. This may have a
negative performance impact if the contraint wraps a large number of routes as the
parameters hash is built by merging GET, POST and path parameters.

Fixes #2510.

In the current router DSL, using the +match+ DSL
method will match all verbs for the path to the
specified endpoint.

In the vast majority of cases, people are
currently using +match+ when they actually mean
+get+. This introduces security implications.

This commit disallows calling +match+ without
an HTTP verb constraint by default. To explicitly
match all verbs, this commit also adds a
:via => :all option to +match+.

Closes #5964

By default, resources routes are created with :resource/:id. A model
defining to_param can make prettier urls by using something more
readable than an integer ID, but since the route picks it up as :id you
wind up with awkward User.find_by_username(params[:id]) calls.

By overriding the key to be used in @request.params you can be more
obvious in your intent.

uses PATCH for the forms of persisted records, and routes PATCH and PUT to the update action of resources

Too painful to lose the compact shorthand form!

This reverts commit e848c525.

Conflicts:

	actionpack/lib/action_dispatch/routing/mapper.rb

Fix url_for method's behavior when it is called with :controller option which starts with "/" from multiple nested controller.

Closes #3864

The commit 4c321c6d removes the path_params variable assignment, actually the entire line is not used at all.

Test for unicode path support

when calling url_for with a hash, additional (likely unwanted) values (such as :host) would be returned in the hash... calling #dup on the hash prevents this

addresses issue #1907 - any routes that follow a route with a constraints
  block are inheriting the previous route's constraints.