Issue#378

* renamed CatrobatProject class to CatrobatProgram class
* now adding globally unique programID to the program directory name that is retrieved from PocketCode's "Catrobat Store"
* to those programs that are generated by the user on the device no programID is assigned (placeholder suffix)
* after uploading the user generated programs to the store a globally unique programID is retrieved from the store and the directory name suffix will be updated