Added empty string option for session_cache_limiter as mentionned in the php manual: "Setting the cache limiter to '' will turn off automatic sending of cache headers entirely."
Adding HHVM to build matrix
Merge pull request #5610 in develop
Merge pull request #5589 in develop
Merge pull request #5512
Make I18n component completely optional for Mvc
Let MVC translator implement all available translator interfaces
Re-add translator interface
Fix interface-change related tests
Fix Zend\File related problem
Prettified output of Zend\Code\Genator\ValueGenerator for multi-line arrays
Corrected ValueGeneratorTest
Merge pull request #5574 in develop
Corrected another failing test
Removing double 'matrix' entry
Fix getCurrentSchema error with MS SQL server
Update Connection.php
added AssertionAggregate and AssertionManager

AssertionAggregate allows aggregating multiple assertion to be associated with one ACL rule. This has been done without modifying a single file of existing code.

AssertionManager is a simple Plugin Manager allowing to declare Acl asseertions as services. It can be used by AssertionAggregate to add assertions by passing their service name. It could also by used by the Acl component itself, and should be declared as a default service, so that it could rely on Config service to get intialized, but those features would need to alter existing code and I didn't want to do that at this time.
minor styling fixes based on @samsonasik comments
changed the shareByDefault value to true for AssertionManager

there's no need for reinstantiating assertions each time it should be verified...