Function: flip_horizontal

--Usage--
> flip_horizontal(input: image)

Flip an image horizontally.

--Parameters--
! Parameter	Type			Description
| @input@	[[type:image]]		Image to flip.

--Examples--
> flip_horizontal("image_logo.png")  ==  [[Image]]
>>> flip_horizontal(<img src="image_logo.png" alt='"image_logo.png"' style="border:1px solid black;vertical-align:middle;margin:1px;" />) == <img src="image_logo_hflip.png" alt='"image_logo_hflip.png"' style="border:1px solid black;vertical-align:middle;margin:1px;" />

--See also--
| [[fun:flip_vertical]]		Flip an image vertically
| [[fun:rotate]]		Rotate an image