Fix the bug introdiced in PR #866, where the $format was never set.
build against Symfony 2.6 instead of Symfony 3.0

After the `2.6` branch has been created on the Symfony repository, the
`master` branch has become the development branch for `3.0`. However,
builds should still happen for `2.6@dev` instead of `3.0@dev` for now.
Merge pull request #904 from xabbuh/symfony-2.6-branch-build

build against Symfony 2.6 instead of Symfony 3.0
Documented listeners priorities
Merge pull request #905 from florianv/doc-priority

Documented listeners priorities
handle StopFormatListenerException in the ExceptionController
make it possible to configure the ExceptionController without the TwigBundle
Merge pull request #897 from mvrhov/fix_866

Fix the bug introdiced in PR #866, where the $format was never set.
Merge pull request #908 from FriendsOfSymfony/exception_controller

Exception controller
Fix that empty default value was converted to an empty array despite of strict mode

If Request parameter is an array without default value, then an error should be thrown that "parameter value is not an array" in strict mode
Updated installation instructions
Merge pull request #913 from javiereguiluz/update_composer_instructions

Updated installation instructions
fix ContainerBuilder mock generation in tests

By default, PHPUnit mocks all methods of the mocked class. This breaks
when one of the methods has an argument that is type-hinted with a
non-existing class or interface.
Merge pull request #914 from xabbuh/fix-tests

fix ContainerBuilder mock generation in tests
Add test that error is thrown when array parameter is missing in request
Merge pull request #910 from eugef/patch-1

Fixed validation for Request parameter that is an array without default value
Add back test case that was deleted by accident
Merge pull request #916 from eugef/patch-1-undelete-test

Add back test case that was deleted by accident
Add allowBlank option to queryparam
fixes issue #814
rebased
Merge pull request #886 from mosch/master

Add allowBlank option to queryparam