Fix/adjust cubemap process
- on linux systems there is an issue with freeing files/memory
- in case of create process is interrupted there is no mechanism to fix that, next cube loading crashes ... idea: add a separate file (txt) to show the create process has been finished (with number of cube probes to make it fail safe) and create all files again in case of negative validation
- adjust clean commands to ditch cm files. each map is creating about 40MB of image files ...