* Using lambdas instead of member function pointers simplifies the command dispatching and reduces the code volume
* Removed duplicate error handling
* Fix for issue #956
* Unit test updates
* Resolved SonarQube issues
* Unit test updates
* Lambda syntax cleanup
* Use new-style casts
* Use std::none_of when saving the cache
* Use to_integer instead of casts
* Use accessors for getting CDB data
* Made ctrl_t private
* Improved encapsulation
* Replaced pointers by references
* Removed all remaining occurrences of DWORD and BYTE, making os.h obsolete
- Moved C++ code to cpp/ from src/raspberrypi
- Related updates to Makefile, easyinstall.sh, and the github build rules
- Removed the native X68k C code in src/x68k from the repo
