Add PHP7 compatible versions for the Null/True/False constraints as they are reserved words in PHP7#14228

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stof merged 1 commit intosymfony:2.3from

stefanruijsenaars:php7-nullconstraint

May 15, 2015

Commits on May 13, 2015

Fixed compatibility with PHP7 and up by introducing new constraints (IsNull, IsTrue, IsFalse) and related validators (IsNullValidator, IsTrueValidator, IsFalseValidator)
stefanruijsenaars
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