Merge branch '2.3'

* 2.3:
  updated versions in the README file
  Remove +x mode on file
  updated doc links
  Fix deprecated function bind
  fixed typo
  updated composer.json
  updated VENDORS for 2.1.10
updated versions in the README file
Created the project basic documentation
Removed Standard's own documentation basic files
Added link to symfony standard edition
Renamed the composer package
Removed the requirement test
Removed Swiftmailer dependance and configuration
Incremented the minimum PHP version to 5.3.17
Used twig without extensions
Used empty (blank) favicons
Removed the changelogs
Removed AcmeDemoBundle
Intercepted redirection in development environment
Added the differences with the standard edition
Fixed composer.json extra commas
Removed broken link to deleted version file
Removed configurator route