Added Lines Before Namespace Fixers

NoBlankLinesBeforeNamespaceFixer is a contrib level fixer, and OneBlankLinesBeforeNamespaceFixer is a symfony level fixer. This also includes some utils refactoring and improvements.
It shows only removal of calculateIndent() https://github.com/GrahamForks/PHP-CS-Fixer/commit/9fc01e64ce74d1acc5c9aa8b22c242bfdbd3524d