added information about upgrading Silex and tweaked Silex version in the docs
added information about upgrading Silex and tweaked Silex version in the docs

RayRutjes/Silex,naderman/Silex,naderman/Silex,jdreesen/Silex,romainneutron/Silex,Xephi/Silex,SpacePossum/Silex,silexphp/Silex,GromNaN/Silex,Incognito/silex-fork,JPry/Silex,lyrixx/Silex,romainneutron/Silex,stof/Silex,peterkokot/Silex,arduanov/Silex,cgsmith/Silex,akucherevskiy/developex_test,GromNaN/Silex,CarsonF/Silex,tcx1000/Silex,Xephi/Silex,mTorres/Silex,stof/Silex,plotek/Silex,plotek/Silex,mathroc/Silex,Tobion/Silex,cesarmarinhorj/Silex,romainneutron/Silex,fhinkel/Silex,beealone/Silex,SanderKnape/Silex,naderman/Silex,mTorres/Silex,RayRutjes/Silex,mathroc/Silex,fabpot/Silex,akucherevskiy/developex_test,Tobion/Silex,stof/Silex,GromNaN/Silex,mmauri04/Silex,jdreesen/Silex,lyrixx/Silex,fabpot/Silex,akucherevskiy/developex_test,JPry/Silex,SpacePossum/Silex,gencer/Silex,cgsmith/Silex,beealone/Silex,tcx1000/Silex,peterkokot/Silex,lokhman/Silex,SanderKnape/Silex,lyrixx/Silex,Incognito/silex-fork,peterkokot/Silex,lokhman/Silex,Tobion/Silex,mmauri04/Silex,arduanov/Silex,CarsonF/Silex,fhinkel/Silex,CarsonF/Silex,cesarmarinhorj/Silex