Description

We want to show elevation of the current mouse position, using an "elevation service/layer" of some sort.

The elevation will be showed when a flag in the MousePosition plugin is enabled (showElevation) and an elevation layer is configured (either in a single map, through json configuration, or globally via localConfig.json).

Other useful information (optional):

We want to support "elevation" layers for all mapping libraries. Initially we will add support to WMS layers, using the BIL format (http://docs.geoserver.org/stable/en/user/community/dds/index.html).
For Cesium, the elevation layer will be used as a terrain provider too.