Added documentation for the :param option for resourceful routing
Remove unnecessary include for integration tests.
Ensure we always use instances of the adapter specific column class

- Create a consistent API across adapters for building new columns
- Use it for custom properties so we don't get `UndefinedMethodError`s
  in stuff I'm implementing elsewhere.
Remove TODO.
Use github url for homepage of log4r [ci skip]
Merge pull request #15399 from tgxworld/remove_todo_router_test

Remove TODO.
Merge branch 'master' of github.com:zackperdue/rails into zackperdue-master
Add @senny's changed from #14741, including code font for `resources`
options, and wrapped to 80 chars. [ci skip]
Add missing `:param` option from the docs for Mapper#match [ci skip]
Option discovered by @zackperdue in #14741, implemented in #5581.
[ci skip] Make last note show up in postgresql guide.
Merge pull request #15403 from JuanitoFatas/doc/pg-guide-note

[ci skip] Make last note show up in postgresql guide.
Merge pull request #15397 from sgrif/sg-column-class

Ensure we always use instances of the adapter specific column class
Merge pull request #15061 from tgxworld/remove_unnecessary_include

Remove unnecessary include for integration tests.
Refactor serialized types to be partially defined as custom properties

Many of the methods defined in `AttributeMethods::Serialization` can be
refactored onto this type as well, but this is a reasonable small step.
Removes the `Type` class, and the need for `decorate_columns` to handle
serialized types.