Uploading images from organizers

The pics about the place where the meeting is hosted, i.e., Royal
Holloway (University of London, Egham, Surrey, England)
Creating and inserting carousel into the index

The following folders and files have been created:
- multimedia/dicty15_carousel: including a selection of images to
create the animated gif file
- The original PSD file to create the animated gif file
- The dicty15_header.gif file in both the multimedia folder and the
public folder.
Merge pull request #36 from dictyBase/feature/dicty15-images-carrusel

Feature/dicty15 images carrusel