Video (VID-1417): VideosModule - added caching
 Video (VID-1417): VideosModule - updated getVideosDetail() function
Video (VID-1417): VideosModule - updated getVerticalVideos() function
Video (VID-1417): VideosModule - adding varnish cache
VID-1423 Whitespace
Video (VID-1417): VideosModule - use shared memcache for vertical videos
VID-1423 only send tracking call if module is visible/displayed
VID-1423 check for related articles instead of videosmodule visibility
VID-1423 check the right element
Merge branch 'VID-1417' into dev
Merge branch 'dev' into VideoSprint42