Place hasArgument() check at the beginning of getArgument() method 

If input definition doesn't have specified argument, then unnecessary operations will be executed ($arguments = is_int($name) ? array_values($this->arguments) : $this->arguments;)
Fix http-kernel dep in symfony/security

The current constraint will not match 2.3.x-dev and cause edge cases
where either:

* composer falls back to symfony/symfony because it cannot find a match
* composer installs 2.2 versions of http-kernel and http-foundation
Added missing information to the UPGRADE-3.0 file and sorted its sections
[Validator] Rename issn constraint message option to be consistent with all constraints having a single message option
merged branch ajgarlag/feature/issn-validator-message-option (PR #7872)

This PR was merged into the master branch.

Discussion
----------

[Validator] Rename issn constraint message option.

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets |
| License       | MIT
| Doc PR        |

Rename issn constraint message option to be consistent with all constraints having a single message option as suggested by @stof at https://github.com/symfony/symfony/commit/a4abfb95509437153bee13f1a49ae74a63408806#L0R23

Commits
-------

57c724a [Validator] Rename issn constraint message option to be consistent with all constraints having a single message option
merged branch alexpods/patch-1 (PR #7864)

This PR was merged into the master branch.

Discussion
----------

Place hasArgument() check at the beginning of getArgument() method

If input definition doesn't have specified argument, then unnecessary operations will be executed ($arguments = is_int($name) ? array_values($this->arguments) : $this->arguments;)

Commits
-------

992c218 Place hasArgument() check at the beginning of getArgument() method
merged branch bschussek/doc-fix (PR #7867)

This PR was merged into the master branch.

Discussion
----------

Added missing information to the UPGRADE-3.0 file and sorted its sections

Commits
-------

7e7e4c0 Added missing information to the UPGRADE-3.0 file and sorted its sections
merged branch igorw/security-constraint (PR #7866)

This PR was merged into the master branch.

Discussion
----------

Fix http-kernel dep in symfony/security

The current constraint will not match 2.3.x-dev and cause edge cases
where either:

* composer falls back to symfony/symfony because it cannot find a match
* composer installs 2.2 versions of http-kernel and http-foundation

Commits
-------

01016be Fix http-kernel dep in symfony/security
[SecurityBundle] fixed deps on the security component