. simplify the interface FrameBase to make it easier to implement it for different cases (remove HDC and make parameters more explicit)
. remove functions which are only called on a Win32Frame (in which case a cast is guaranteed to succeed)
. otherwise there is the risk that every FrameBase implementation wants to add its own variants.
. FrameBase::FrameRefreshStatus() simplify implementation: pass all flags explicitly
* Interface.h: ensure that functions in the interface are not exported by other header files.
This is generally harmless, except for the presence of default arguments, in which case the version with default arguments must come first.
To avoid the issue, these functions are only ever exported in the Interface.h header file.
This is not complete as header files from Windows/.. are still included in:
Keyboard.cpp
SerialComms.cpp
Joystick.cpp
But probably these are arch specific and will have to be completely reimplemented elsewhere.
