[NTVDM]

[NTVDM]
- Add DPRINTs to the DumpMemory function.
- Use a VgaSetActiveScreenBuffer function to change active screen buffers: it calls the SetConsoleActiveScreenBuffer API but also recreates the VDM console menus, because on windows custom console menus are per-screen-buffer, and not per-console, so that if you set menus when one screen buffer is activated, and if you change it, then your menus become unuseful because for this new active screenbuffer, they are not set. It's completely ridiculous but we need to live with that (on ReactOS we still don't have this behaviour).

svn path=/trunk/; revision=64137