exclude parts that have different default values

fixes test break in HHVM due to export of a closure

issue #4687

also fixed an issue with default value loading of bool columns.

fixes #3489, fixes #4085, fixes #3920
related to #4672

fixes #4654

close #4655

- can be used to enable caching in a request without the need for any storage
- useful for example in complex console tasks that should still be independed

Added support for arbitrary operators to Query::filterWhere, added support for arbitrary operators to Sphinx extension

Fixes #4489: RBAC PhpManager wasn't saving multiple assignmentsFixes #4489: RBAC PhpManager wasn't saving multiple assignments properly

Security component adjustments: fixed comment style, hkdf() and pbkdf2() are now protected, compareString() is now public

Fixes #4453: `yii message/extract` wasn't properly writing to po files in case of multiple categories