Put attr_reader in with all of the other instance methods

Delegate `type_cast_for_write` to injected type object

Check authentication scheme in Basic auth

Inline typecasting helpers from Column to the appropriate types

Use the generic type map for PostgreSQL OID registrations

Delegate predicate methods to injected type object on Column

Use the generic type map object for mysql field lookups

Distinguish rake assets:clobber from rake assets:clean

[ci skip]

Replace `type_cast` case statement with delegation

Fix confusing exception in ActiveSupport delegation

Have Postgres OID types inherit from general types

Use general types for mysql fields

All subclasses of column were now delegating `type_cast` to their
injected type object. We can remove the overriding methods, and
generalize it on the `Column` class itself. This also enabled us to
remove several column classes completely, as they no longer had any
meaningful behavior of their own.

Delegate type_cast to injected type object in mysql

Using general types where possible. Several more can go away once
infinity gets figured out.

Delegate `#type_cast` to injected type objects on SQLite3