This PR fixes #8930 and some stuff from #8985

Reorder query in active record query of rails guide [ci skip]

this decouples our code from the env hash a bit.

Removed not used code

Push limit to type objects

Columns and injected types no longer have any conditionals based on the
format of SQL type strings! Hooray!

Push precision to type objects

Push scale to type objects

Rename `stack` to `queue`

Ideally types will be usable without having to specify a sql type
string, so we should keep the information related to parsing them on the
adapter or another object.

Move `extract_precision` onto type objects

Remove unnecessary `Hash#to_a` call

Because it is used as a queue (FIFO), not as a stack (LIFO).

* http://en.wikipedia.org/wiki/Stack_(abstract_data_type)
* http://en.wikipedia.org/wiki/Queue_(data_structure)

Inspired by https://github.com/rails/rails/commit/931ee4186b877856b212b0085cd7bd7f6a4aea67

```ruby

def stat(num)
  start = GC.stat(:total_allocated_object)
  num.times { yield }
  total_obj_count = GC.stat(:total_allocated_object) - start
  puts "#{total_obj_count / num} allocations per call"
end

h = { 'x' => 'y' }

stat(100) { h.     each { |pair| pair } }
stat(100) { h.to_a.each { |pair| pair } }

__END__
1 allocations per call
2 allocations per call
```

Use `break` instead of `next` in AD::Journey::Formatter#match_route

Use the generic type map for all PG type registrations

Allow additional arguments to be used during type map lookups

We're going to want all of the benefits of the type map object for
registrations, including block registration and real aliasing. Moves
type name registrations to the adapter, and aliases the OIDs to the
named types

Determining things like precision and scale in postgresql will require
the given blocks to take additional arguments besides the OID.

- Adds the ability to handle additional arguments to `TypeMap`
- Passes the column type to blocks when looking up PG types

[Guides] Do not gsub non ASCII characters in header anchor.

It was changed by mistake at c5d64b2b.

The array is sorted in descending order, so there is no point in
iterating further if we met a negative item - all the rest will be
negative too.

Form full URI as string to be parsed in Rack::Test.

There are performance gains to be made by avoiding URI setter methods.

Fixed a problem where `sum` used with a `group` was not returning a Hash.

Most recent change should be moved to the top