• Updated to compile with latest master.
• Increased Windows ABI level to 8.1 now that the Windows 7 and 8 support is dropped. I had to delete some structures to avoid compile errors.
• Enabled Direct Manipulation on Windows 8 or greater instead of Windows 10 only.

Update only the active window.

• Move DM code to new files.
• Fix viewport not resetting when user moves cursor by increasing viewport size.
• Fix stuck pinch gesture by increasing epsilon.
• Adress review comments.

Thanks for the explanation. I redefined all required structs for DM API.

Don't change Windows API version.

Added check for Windows version.