CMS-3460 Keyboard shortcuts to Close and Delete actions does not work when an input has focus

Make Close and Delete combinations global so Mousetrap will allow them inside inputs; change close combination to mod+alt+f4 since mod+f4 is Chrome combination to close tab
Merge pull request #753 from enonic/CMS-3460

CMS-3460 Keyboard shortcuts to Close and Delete actions does not work wh...