Removed 2.2 references as it reached eom
executable permission unset
Removed assignment operator
Added example of range operator
links in documentation overview contributing moved to bottom
Fixed namespace in Handling Form Submissions standalone example.
Added docs for using functions
Added article about custom functions
Merge pull request #3233 from peterkokot/patch-2.4

Executable permission unset
some tweaks for #3190
[#3022] Adding service container expression language details
[#3232][#3022] Making many small tweaks thanks to @WouterJ and @xabbuh
Merge pull request #3232 from symfony/expression-framework-container

[#3022] Adding service container expression language details
Merge pull request #3238 from peterkokot/patch-2

Links in documentation overview contributing moved to bottom
Merge pull request #3239 from zsjavorszky/fix_form_handling_example

Fixed namespace in Handling Form Submissions standalone example.
Merge pull request #3241 from WouterJ/expression-furthering-component

Continuing ExpressionLanguage component docs
[#3241] Minor tweaks to new expression language functions
fix two little syntax errors
[Cookbook][Configuration] Fix front controller sample code
[Cookbook][Console] Fix statement