Feature/filesystem cleanup (#1587)

* Adapting to the changes in Ghoul
* First step of moving filesystem functions to std
* Remove persistence flag from cachemanager

modules/spacecraftinstruments/rendering/renderablemodelprojection.cpp

@@ -183,7 +183,7 @@ void RenderableModelProjection::initializeGL() {
 
     _projectionComponent.initializeGL();
 
-    float bs = boundingSphere();
+    double bs = boundingSphere();
     _geometry->initialize();
     setBoundingSphere(bs); // ignore bounding sphere set by geometry.
 }