* Initial restructuring of the Globebrowsing branch

* Update Ghoul repository
Fix include guards

* More cleanup

* Split texttileprovider subclasses into separate files

* Move TileProviders into namespace

* Convert static class methods into free functions

* Splitting tile subclasses into their own files
Remove `using namespace` from header file

* Split TileDataSet subclass into separate file
Update SGCT reference

* Move shader preprocessing data into internal class

* More Globebrowsing cleanup

* More cleanup
Remove unused Convexhull class