Windows: implement resize increments

[tetrahedron341]

• Tested on all platforms changed (windows)
• Added an entry to the changelog module if knowledge of this change could be valuable to users
• Updated documentation to reflect any user-facing changes, including notes of platform-specific behavior
• Created or updated an example program if it would help users understand this functionality
• Updated feature matrix, if new features were added or implemented

Implements #135 on windows

[madsmtm]

CC @Cthutu, does this work for you?

[Cthutu]

I managed to emulate it with resizing during a resize event (which surprisingly worked well). But I will try this when I get a chance.

[msiglreith]

thanks looks good, didn't notice any issues during testing