Update preview_mode.rst
Update preview_mode.rst
added some preview mode screenshots
cropped screens
Update preview_mode.rst
Update preview_mode.rst
Update preview_mode.rst
Merge remote-tracking branch 'base/master'

Conflicts:
	Resources/doc/reference/preview_mode.rst
add wip recipe for custom action
Update layout.css
fixed some formatting and typos
Update recipe_custom_action.rst

fixed xml closing bracket
Merge pull request #1 from YesCT/patch-1

Update recipe_custom_action.rst
Update recipe_custom_action.rst

fixed a few more little things, 
in restructured text,
fixed grammar (sentence),
kept code style of ->add ... ending with ; on own line, lining up with statement beginning.
Merge pull request #2 from YesCT/patch-2

Update recipe_custom_action.rst
Added support for KnpMenu v2-alpha /!\ UNSTABLE
Specify the error message
Add throw StringCastException
Fixed lithuanian translation: added missing plural rules.
Updated lithuanian translation.