Convert airphoto viewer from mapserver to geoserver

[mraross]

Convert airphoto viewer network links from mapserver to geoserver. The resulting app should be kept in dbc-kml-apps/apps and look like the mapserver app as much as possible.

Migrating the viewer takes four steps:

1. For each simple GroundOverlay, Replace each mapserver network link with the appropriate geoserver network link from the BC Web Mapping Library

2. For each mapserver network link that needs to allow a user to click on a placemark to view feature details,
   2.1 Replace the mapserver network link with the appropriate geoserver network link from the BC Web Mapping Library. Note the shape files used in mapserver need to be loaded into the WhereHouse, styled, and defined in GeoServer before they will appear in the before they will appear BCGov_Web_Map_Library. Angus Christian is point man on the GeoBC side for that. Not sure who in Data Admin is assigned to this.
   2.2 Customize the network link and associated layer definition in geoserver by defining description.ftl and title.ftl templates and putting them into the appropriate subdirectory under geoserver/templates
   2.3 Further customize the network link and associated layer definition in geoserver by defining named styles (e.g., SLDs) that reference kml icons held in this repo.

3. Update all icon links to use the following production RawGit base urls:

    for geocoder-related icons
         use https://cdn.rawgit.com/bcgov/ols-devkit/df422089/kml/icons/geocoder
   
    for databc logo icon
         use https://cdn.rawgit.com/bcgov/ols-devkit/df422089/kml/icons/DataBC_logo.png
   
   for all other icons
        use https://cdn.rawgit.com/bcgov/dbc-kml-apps/62ebb524/kml/icons
   

There is no need to change any network links that reference DataBC location services (e.g., geomark, geocoder, geonames)

[webgismd]

Please note that the UMN Mapserver is pointing to shapefiles that Carol and Angus will be working on modelling and getting into the BCGW database. So currently equivalent network links don't exist in the BC Web Map Library KML. http://apps.bcgov/wsvn/Webmapping.HOSTsetup/trunk/mapfiles/airphoto_viewer6.map

[mraross]

This issue depends on #15