update install instructions for symfony 2.1
Merge pull request #190 from jrobeson/update-sf2.1-install-instructions

update install instructions for symfony >=2.1
Fixed the composer requirements to allow Sf 2.3

Fixes #191
Changed the DoctrineExtesions' official documentation's uri.

Fix #198
Merge pull request #199 from BraisGabin/patch-1

Changed the DoctrineExtesions' official documentation's uri.
Allow to configure Sluggable managed filters
 li
CS fix
Merge branch 'master' of https://github.com/stanislavprokopov/StofDoctrineExtensionsBundle