[1.2.0] Fixed CS

Ran php-cs-fixer fix src
[1.2.0] Code review
[1.2.0] Updated CHANGELOG
[1.2.0] Added InputSanitizer documentation
[1.2.0] Took @WouterJ feddback into account
[1.2.0] Updated CHANGELOG
Merge pull request #83 from gnugat/1.2.0

1.2.0 Release