Use image fields in leaflet popups

I have created two issues for the leaflet module, one as a feature request, and the other as a bug In order for the gpx_image module to work with multivalued image fields the user has to merge the two patches, or need to reroll one of them. I have made things easier an merged the 2 patches. Apply it to the current version of the leaflet module, and you will be able to use multivalued image fields as popups.