made the logger optional in AdminExtractor
Update advance.rst

Fixed error in documentation.
Looks like admin->routerBuilder was renamed to routeBuilder, but documentation doesnt reflect it.
Update advance.rst

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Update advance.rst

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Update advance.rst

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Update advance.rst

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Update advance.rst

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Update advance.rst

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Added details for currency type

I've been looking for a few minutes what to provide as option and figured out it's an ISO code, i think it'll help many users to add this in doc.
added addConstraint() to ErrorElement closes #1200
updated Resources/doc/reference/conditional_validation.rst
Update Admin toString method

As the getSubject method may return a boolean, the toString method can throw an exception.
Add missing unit test
Little warning about __toString in documentation
Moving previous commited doc from Architecture to a dedicated Troubleshooting page.
Fix typo in troubleshooting
Fix #1226
Update base_edit_form.html.twig
Manually apply https://github.com/sonata-project/SonataAdminBundle/pull/1202
fix a typo in german translation