Https for markers and images

Url for markers and images changed to // to avoid the
'Blocked loading mixed active content' issue in Firefox when the
KML is used on a https site.
* markers in FormatKml.php
* image in CommonFunctions.php

Change-Id: I17e562f983fd7da6d72c77a9f5327d09c48fc1cd
Merge "Https for markers and images"