. 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
* Video / FrameBase: move arch specific code to FrameBase.
* Video::Initialize & SetFrameBuffer.
Ensure initialization and SetBuffer can only happen in the right order.
* Video: move virtual functions to FrameBase.
With these changes all the virtual functions are in FrameBase and Video gets closer to be (only) the Apple ][ Video device.
* Move a few more functions from Video to FrameBase (snapshot related)
Now, the inclusion is one way with Video *not* including FrameBase.
* FrameBase::VideoRefreshScreen move Video related code to Video.
And only leave management to FrameBase.
