Fix mismatches between the PHPDoc and the method signatures
fix small typo
Update library/Zend/Http/Headers.php

fix phpdoc
Merge commit 'refs/pull/3887/head' of github.com:zendframework/zf2 into hotfix/typo
Merge pull request #3827 from micheh/hotfix/phpdoc-mismatch

Fix mismatches between the PHPDoc and the method signatures