Update Changlog for v1.1
Remove need for cattr_accessor

Adds a couple of modules to contain the class attributes previously
used with the Railsism of `cattr_accessor`. The modules are inline
with the classes to make them ugly and force me to remove them
eventually.
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Fix incorrect error class
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Remove blank? usages
Refactor extension handling in `::parse`

* Use the built-in support for the extension option
* Remove usages of `#present?`
* Add test for extension handling.
Remove last present? usage
Remove support monkeypatches

All instances of `#present?` and `#blank?` have been removed and
replaced (more verbose) alternatives. This means we don't need to
check for `ActiveSupport` anymore and there is no monkeypatching
of objects. Yay!
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