This reverts commit fa6d921e.

Reason: Not a fan of such massive changes. We usually close such changes
if made to Rails master as a pull request. Following the same principle
here and reverting.

[ci skip]

For future reference, this is the regex I used: ^\s*#\s*\n(?!\s*#). Replace
with the first match, and voilà! Note that the regex matches a little bit too
much, so you probably want to `git add -i .` and go through every single diff
to check if it actually should be changed.

This reverts commit 174cf8b2, reversing
changes made to 7ecd6a73.
The reverted commit improved the performance in the wrong place, now we
have added this 6ddbd184 improvement.

stringified keys

Clean up routes inclusion and add some comments for the next soul that decides to adventure on this code.

:subdomain can now be specified with a value of false in url_for, allowing for subdomain(s) removal from the host during link generation. Closes #2025

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

:subdomain, :domain and :tld_length options can now be used in url_for, allowing for easy manipulation of the host during link generation.
Signed-off-by: NJosé Valim <jose.valim@gmail.com>

Avoid (@_var ||= nil) pattern by using initialize methods and ensuring everyone calls super as expected.

Signed-off-by: NSantiago Pastorino <santiago@wyeworks.com>

mounted_helpers are a bit similar to url_helpers. They're automatically
included in controllers for Rails.application and each of mounted
Engines. Mounted helper allows to call url_for and named helpers for
given application.

Given Blog::Engine mounted as blog_engine, there are 2 helpers defined:
app and blog_engine. You can call routes for app and engine using those
helpers:

app.root_url
app.url_for(:controller => "foo")
blog_engine.posts_path
blog_engine.url_for(@post)

* added more tests for prefix generation
* fixed bug with generating host for both prefix and url
* refactored url_for method
* organized tests for prefix generation

A few examples:
url_for Blog::Engine, :posts_path
url_for Blog::Engine, @post
url_for Blog::Engine, :action => "main", :controller => "index"

It's based specifying application's script_name with:
Rails.application.default_url_options = {:script_name => "/foo"}

default_url_options method is delegated to routes. If router
used to generate url differs from the router passed via env
it always overwrites :script_name with this value.

This requires knowledge about original SCRIPT_NAME and
the parent router. It should be pass through the env
as ORIGIAL_SCRIPT_NAME and action_dispatch.parent_routes

This technique is here to allow using routes from Engine in Application
and vice versa. When using Engine routes inside Application it should
generate prefix based on mount point. When using Engine routes inside
Engine it should use env['SCRIPT_NAME']. In any other case it should
generate prefix as env should not be even available.

options could be of any kind of Hash (Hash, HashWithIndifferentAccess or OrderedHash) this way we keep the properties of the options passed as an argument

Signed-off-by: NJosé Valim <jose.valim@gmail.com>

Signed-off-by: NJosé Valim <jose.valim@gmail.com>