Support the old AppleWin 1.25 vertical blending for hires:
- extended Config dialog to include 'Vertical Blend' checkbox
- Persist 'Video Styles' to Registry
- new cmd line options to select this style & also select 'RGB (Color Monitor)'
- code refactor to support enum VideoStyle_e (and replaced g_uHalfScanLines with a bit in g_eVideoStyles)
Bumped version to 1.28.2.0.
Changes to ease code compilation in GCC.
Disk_t and HDD contain a std::string and for this reason they need a proper constructor, ZeroMemory is not guaranteed to work.
