Spanish language support
Fixes a strange issue where a <button> inside a nested <form> will trigger the event twice (1 for button, 1 for form)
Merge pull request #723 from alvaro-canepa/patch-1

Add Spanish language support
When cms.disableCoreUpdates is set to true the Backend will no longer display updates for the core.
If there is no build number, don't display the build scoreboard item
Subsequent expressions are on a new line (see developer guide > PSR exceptions)
Minor
Update contributing