Solves #9 (Show overlay during page initialization so that navigation menu for mobile is not visible, uncollapsed)

Change scale image name to grid-teaser (#10 of sdswas.theme) and solves part of issue #24 (Perform automatic cropping of any image that has to be displayed with a specific aspect ratio)

Solves #23([BUG] Add to calendar and register buttons are missing in the Event modal window (Rodolfo template))

Allow images in generic event content type, show them in the full view with a boostrap carousel and solve a bug in the uninstall of the addon

Container content type SDS EVENT and contained content types WEBINAR, GENERIC EVENT and PRESENTATION