Sometimes it is not necessary to include the whole Cutter.h file
Hence, it's been splitted so you can include only what you require
E.g. #include "core/CutterCommon.h" to have access to the common types
* Implemented macOS open with functionality and drag of files to the icon
* fixed bug when dropping a different binary
* fixed Uppercases for application names
* refactor to avoid code in header for CutterApplication
* removed unused includes
* more consistent includes and main.cpp cleanup