Add a new include path to the base shader folder

Move the RenderableStars shaders into a separate folder

src/engine/openspaceengine.cpp

@@ -174,6 +174,9 @@ bool OpenSpaceEngine::create(int argc, char** argv,
 	FileSys.createCacheManager(absPath("${" + constants::configurationmanager::keyCache + "}"));
 	_engine->_console.loadHistory();
 
+	// Register the provided shader directories
+	ghoul::opengl::ShaderObject::addIncludePath("${SHADERS}");
+
 	_engine->_syncBuffer = new SyncBuffer(1024);
 
 	// Determining SGCT configuration file

src/rendering/stars/renderablestars.cpp

@@ -129,12 +129,9 @@ bool RenderableStars::initialize() {
 	bool completeSuccess = true;
 
 	_program = ghoul::opengl::ProgramObject::Build("Star",
-		"${SHADERS}/star_vs.glsl",
-		"${SHADERS}/star_fs.glsl",
-		"${SHADERS}/star_ge.glsl");
-	//_program = ghoul::opengl::ProgramObject::Build("Star",
-	//	"${SHADERS}/star_vs.glsl",
-	//	"${SHADERS}/star_fs.glsl");
+		"${SHADERS}/modules/stars/star_vs.glsl",
+		"${SHADERS}/modules/stars/star_fs.glsl",
+		"${SHADERS}/modules/stars/star_ge.glsl");
 	if (!_program)
 		return false;
 	_program->setProgramObjectCallback([&](ghoul::opengl::ProgramObject*){ _programIsDirty = true; });