Add FlipHorizontal, FlipVertical, ApplyDrawFullPathsInCenter, Assign function for fast copy.

[wqmeng]

Hello,

I've recently been working on SVGIconImageList and added some features, such as FlipHorizontal, FlipVertical, and ApplyDrawFullPathsInCenter. These features may be useful to some users.

I hope this feature can be committed to the master branch.

Thank you very much.

[carloBarazzetta]

Great Job! Please send a pull request to Angus Johnson, the creator of Image32 library, because the changes made to Img32.SVG.Reader.pas must be included into his librarary, so we can always be aligned to Image32 project Then, when he accepted your changed for this unit I can accept this Pull request ;-) Thank you.