Feature/gb gui (#390)

Implemented new GUI component to handle WMS servers
* Add Lua scripts to support adding GIBS datasets (closes #222)
* Add Lua function to load WMS servers from a predefined file

* Workaround for Visual Studio 15.3 compile fix in Windows headers

* Initial support for parsing GetCapabilities file and automatically add layers

* Add a Trigger property to remove a layer

* Support default servers

* Add default file

* Move WMS server code from GUI component into GlobeBrowsingModule

* Add Lua scripts for loading and removing WMS servers
Automatically load default servers on startup

* Reset tile provider before removing a layer tolimit the crash risk
Add "From focus" button to switch globebrowsing gui to the same node as the focus

* Remove warnings
Remove compile error with nonexisting GDALOpenEx function

data/globebrowsing_servers.lua

@@ -0,0 +1,38 @@
+-- This file contains a list of default servers for globes that can be used in the GUI
+-- to easily add layers
+
+return {
+    Earth = {
+        {
+            Name = "GIBS",
+            URL  = "https://gibs.earthdata.nasa.gov/twms/epsg4326/best/twms.cgi?request=GetTileService"
+        },
+    },
+    Moon = {
+        {
+            Name = "OnMoon LMMP",
+            URL  = "https://onmoon.lmmp.nasa.gov/wms.cgi?request=GetCapabilities"
+        },
+    },
+    Mercury = {
+        {
+            Name = "USGS Mercury",
+            URL  = "https://planetarymaps.usgs.gov/cgi-bin/mapserv?map=/maps/mercury/mercury_simp_cyl.map&service=WMS&request=GetCapabilities"
+        },
+    },
+    Callisto = {
+        {
+            Name = "USGS Callisto",
+            URL  = "https://planetarymaps.usgs.gov/cgi-bin/mapserv?map=/maps/jupiter/callisto_simp_cyl.map&service=WMS&request=GetCapabilities"
+        },
+    },
+    Deimos = {
+        {
+            Name = "USGS Deimos",
+            URL  = "https://planetarymaps.usgs.gov/cgi-bin/mapserv?map=/maps/mars/deimos_simp_cyl.map&service=WMS&request=GetCapabilities"
+        },
+    },
+}
+
+
+-- https://astrowebmaps.wr.usgs.gov/webmapatlas/Layers/maps.html

data/scene/default.scene

@@ -56,6 +56,10 @@ function preInitialization()
         "openspace.setPropertyValue('*Trail.renderable.Enabled', false)",
         "Disables visibility of the trails"
     )
+
+    openspace.globebrowsing.loadWMSServersFromFile(
+        openspace.absPath("${OPENSPACE_DATA}/globebrowsing_servers.lua")
+    )
 end
 
 function postInitialization()