custom recordign area

[julapy]

hi @Akevlam,

here is the code for recording a custom area of the screen.

this is just what i got working and you might want to refactor the code so that it gels better with the rest of your plugin.

ive added a couple methods in iVidCapProVideo.cs

• SetCaptureRect
• SetCaptureRectWithNormalisedScreenCoordinates

ive also removed SetCaptureViewport function as it now seemed redundant.

i wanted to have the entry point functions for changing the capture rect inside iVidCapPro.cs
but that would require refactoring the begin record function to accept a rect, rather then just width and height of the video. so thought that you'll probably have a better idea of how the API for the plugin should work...

let me know if you have any questions about the changes in the PR.