Update Configuration.php

Adding the option to set index_analyzer and search_analyzer to _all field.
stop config from adding empty arrays into type mappings
Make it possible to disable flush event through configuration
Merge pull request #560 from cassianotartari/master

Update Configuration.php
Merge pull request #562 from evillemez/config

stop config from adding empty arrays into type mappings
Merge pull request #571 from tPl0ch/feature-flush-event

Make it possible to disable flush event through configuration
Merge branch 'master' of https://github.com/FriendsOfSymfony/FOSElasticaBundle
Fixed tests from 571 updates