In-application ability to rename presets

[ahydronous]

Seems like it'd be a nice feature instead of the create new preset > load old preset > save old preset settings into new preset name dance.

Or I'm a buffoon and completely overlooking the way to do it haha.

[wwmm]

Somehow I never had the need to rename these files. Maybe because I do not have an insane amount of presets like some users have. It is a feature to consider.

[wwmm]

Implemented in our master branch.