Added all php file headers

* All headers follow FOS format, defined in https://github.com/FriendsOfSymfony/friendsofsymfony.github.com/issues/14#issuecomment-1236022
Merge pull request #80 from mmoreram/feature/php-file-headers

Added all php file headers
Added all php file headers

* All headers follow FOS format, defined in https://github.com/FriendsOfSymfony/friendsofsymfony.github.com/issues/14#issuecomment-1236022
Improved the Travis configuration

- add testing on HHVM and PHP 5.6
- test the non-latest versions of Symfony only once instead of doing it for all PHP versions, thus reducing the matrix
- build only the master branch and the release branches to avoid extra builds when using the main repo for feature branches
- let composer use individual components and bundles for the normal resolution of Symfony
Merge pull request #82 from FriendsOfSymfony/travis_improvements

Improved the Travis configuration
Merge pull request #81 from mmoreram/feature/php-cs-fixer

Applied Fabpot php-cs-fixer to all code
fix typo in InvalidTagException
Disallow build failures on HHVM
Added a missing property declaration
Added a missing property declaration
Convert docs to reST

Partly convert docs to reST

Move config docs

Convert event subscribers chapters

Set default language to PHP

Refactor docs

Fix code indent