Plone.app.textfield

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- Add equality check (`__eq__`) for RawValueHolder and RichTextValue;
[davisagli]

- Fix marshaler decode to always decode raw value into unicode
[datakurre]

- Remove utils.getSiteEncoding, which was deprecated and not used anywhere.
[thet]

- For Plone 5, support getting markup control panel settings from the registry,
while still supporting normal portal_properties access for Plone < 5.
[thet]

- Resolved an interesting circular import case, which wasn't effective because
of sort order of imports
[thet]

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* Force WYSIWYG, so when we start with 'text/plain' (or another MIME),
selecting 'text/html' will cause TinyMCE to spring into life.
[lentinj]

* Tell Products.TinyMCE what the MIME type is, so it doesn't have to work it out.
[lentinj]

- Use closest_content to navigate through the sea of subforms to
find something that we can use portal_url on.
[lentinj]

- Do not give an error when the raw value is not unicode and isn't
ascii. In that case, encode as unicode then decode as the proper
string, bang head on desk.
[eleddy]

- Internationalization.
[thomasdesvenain]

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- Do not give an error when the raw value is None. Give an empty
unicode string as output in that case.
[maurits]

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* Add support for collective.ckeditor.
[tschorr]

------------------

* Fix compatibility with Zope 2.12. [davisagli]

----------------

* Pass field's max_length to the wysiwyg macro, if it has one.
[davisagli]

* Determine which editor's wysiwyg_support template to use from within
widget_input.pt. Fixes support for collective.ckeditor.
[tschorr, davisagli]

* Update getSite import locations.
[hannosch]

* Make sure that the display widget absolutizes relative links relative
to the correct context. To facilitate doing this from custom templates,
RichTextValue now has an ``output_relative_to`` helper method which
can be passed a context.
[davisagli]

* Fix an issue with the support for plone.schemaeditor.
[davisagli]

* Support a ``max_length`` parameter for RichText fields. Input longer
than the max_length does not pass validation.
[davisagli]

* Pass some additional context to the wysiwyg_support macro to help with
determining the field's mimetype.
[davisagli]

* Changed deprecated getSiteEncoding to hardcoded `utf-8`
[tom_gross]