[reledit] Fix reledit icons jumpiness (closes #4106867) Introduce an "invisible" class (copied verbatim from Bootstrap) that only sets the "visibility" property. "display: none" is the reason for the whole jumpiness as it actually detaches the element from the rendered layout. "visibility: hidden" only makes it transparent while keeping its original box properties (width, height, etc).

include *.py
include */*.py
recursive-include data *.gif *.png *.ico *.css *.js
recursive-include i18n *.po
recursive-include wdoc *