Changes to BC and behavior in version 5.1

Changes to BC and behavior in version 5.1
=========================================

INI setting changes
-------------------


Change of behavior
------------------

- Fixed EZP-19889: eZSelectionType-> hasObjectAttributeContent now returns TRUE
  only if at least one selection is made, otherwise FALSE. In previous releases
  this method always returned TRUE

- Fixed EZP-20289: Symfony CSRF protection not integrated with legacy

  Changed ezFormToken to do csrf protection in same way as Symfony meaning
  there is now a new setting that must be set pr project to accomplish good
  security, set site.ini\[HTMLForms]\Secret on pure legacy/4.x setup.

  If your running Exponential 5.x, the already existing yml parameter %secret%
  will be automatically injected to eZFormToke for you, assuming
  config.yml framework.csrf_protection is set to true (enabled).

- Redirect from modules to untrusted hosts are now forbidden and will end to a HTTP 403.
  You can add hosts to the whitelist in site.ini/[SiteSettings].AllowedRedirectHosts array.


Removed features
----------------

- eZContentOperationCollection::publishContentObjectRelations()

  Was used for processing relations through ezcontentobject_link.op_code column.
  Handling relations in this way was removed as extraneous.
  See issue EZP-20239.

- eZDBFileHandler and eZFS2FileHandler handlers have been removed since they
  were obsolete and replaced by eZDFS ones.


Removed constants
-----------------



Removed globals
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Deprecated
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