Solves bug "Add to calendar" and "Register" buttons are not displayed if the event is upcoming but has already started

Set image field to be mandatory in events because when they are upcoming it is needed in the upcoming events view

Solves bug “For event that last more than one day, the duration field  is not properly computed and it is showing one day less than expected”

Do not show Presentations section either if the folder does not exist or it is empty or only contains unpublished items

Change HTML structure of images section in Past Events in order to show up to 6 bullet navigation items

Remove the JS code of Events and Event view pages (already in main.js) and highlight the page in the header when its HTML is loaded

When there are no upcoming event, show the message “There are no Upcoming events at this moment.” plus a link to explore all events in the home’s section

Solves issue #52 (Add search functionality to the Presentations section of a Past Event) but without loading animation yet and solves issue # 50 (Do not allow to open the full view of a Past Event Presentation from the presentations grid) but the preview link is still visible

Solves bug “Upcoming events section of the Events page shows up to 2 items but it should be up to 3”

Solves bug “Modal windows that are opened from the Events page does not have the functionality to be closed when the user clicks outside them

Remove autocomplete functionality from the search input of Past Events and Presentations grids because it is not properly styled in Chrome browser at least (a blue background appears when the user selects an option )

Remove import of event_presentations.js from events.js because it has been set as a requireJS dependency

2 issues: 1) Prevent JS files to being cached by adding version parameter to the file 2) Move images slider code to main.js