Added Incenteev ParameterHandler to ignore the parameters.yml file

This tool allows to create the parameters.yml file when running ``composer install`` based on the ``parameters.yml.dist`` file, which can then be kept ignored. It will ask interactively for missing values, using the value of the dist file as default value (or using it directly if composer is run non-interactively). More details are available in the [Readme](https://github.com/Incenteev/ParameterHandler/).

this should help people avoiding the warning about commited parameters.yml file.