iOS/MacOS C++11 header compatibility

The proposed header changes allow reuse of the communication header
stack for a C++11 iOS and MacOS project.
In c_com.h
- Optional Pragma packs are used so structures are packed for the
stream.
- Optionally remove the Payload convenience members.
In bytecodes.h
- Give the macro expressions an explicit type - required for use in
C++11 initializer lists
In lms2012.h
- Help resolve the everybody wants to define true/false problem