Add support for converting and rendering volumetric data in the cdf format. Replace DataConverter by a more general purpose TaskRunner.

Conflicts:
	modules/volume/CMakeLists.txt
	modules/volume/linearlrucache.h
	src/engine/openspaceengine.cpp

include/openspace/util/taskloader.h

@@ -0,0 +1,17 @@
+#ifndef __TASKRUNNER_H__
+#define __TASKRUNNER_H__
+
+#include <string>
+#include <ghoul/misc/dictionary.h>
+#include <openspace/util/task.h>
+
+namespace openspace {
+class TaskLoader {
+public:
+    std::vector<std::unique_ptr<Task>> tasksFromDictionary(const ghoul::Dictionary& dictionary);
+    std::vector<std::unique_ptr<Task>> tasksFromFile(const std::string& path);
+};
+
+}
+
+#endif