New Text source

Initial implementation of Text Source, displaying free text or subtitle file. support for Pango font description and formatting tags via gstreamer textoverlay plugin. Saving and loading in XML, GUI for creation (in patterns) and for editing.

src/Decorations.cpp

@@ -460,6 +460,8 @@ Symbol::Symbol(Type t, glm::vec3 pos) : Node(), type_(t)
         shadows[SHARE]  = shadow;
         icons[RECEIVE]  = new Mesh("mesh/icon_receive.ply");
         shadows[RECEIVE]= shadow;
+        icons[TEXT]     = new Mesh("mesh/icon_text.ply");
+        shadows[TEXT]   = shadow;
         icons[DOTS]     = new Mesh("mesh/icon_dots.ply");
         shadows[DOTS]   = nullptr;
         icons[BUSY]     = new Mesh("mesh/icon_circles.ply");