Linux fixes clang (#1216)

* Changes to work on Linux.

* Multiple small fixes for Linux.

* Changes to have trails working on Linux again.

* Bring back AA Trail Lines on Linux.

* Included new branch with correction in cfitsio library linking.

* Updated SGCT.

* Changes to work on Linux.

* Remove extra #endif

* Changes to compile in Clang on Linux.

* Other fixes.

* Bring back some of the changes lost and updated clang building commands.

* requiring 10.15 for sgct, upadating sgct

Co-authored-by: Jonathas <jon.costa@gmail.com>
Co-authored-by: Tom Schober <tom@tomschober.com>
Co-authored-by: Alexander Bock <mail@alexanderbock.eu>

modules/base/rendering/renderabletrail.h

@@ -182,10 +182,15 @@ private:
 
     /// Program object used to render the data stored in RenderInformation
     ghoul::opengl::ProgramObject* _programObject = nullptr;
-
+#ifdef __APPLE__
+    UniformCache(opacity, modelView, projection, color, useLineFade,
+                 lineFade, vertexSorting, idOffset, nVertices, stride,
+                 pointSize, renderPhase) _uniformCache;
+#else
     UniformCache(opacity, modelView, projection, color, useLineFade, lineFade,
         vertexSorting, idOffset, nVertices, stride, pointSize, renderPhase,
         resolution, lineWidth) _uniformCache;
+#endif
 };
 
 } // namespace openspace