Render Texture

This plugin creates a new image having texture synthesized from the selection.

It hides several steps to set up and use the resynthesizer. It requires the separate resynthesizer plug-in.

See the Resynthesizer author Paul Harrison's website, about using the resynthesizer to generate textures.

The effect for users:
Similar to "Fill resynthesized pattern" except:
- here the arguments are reversed: you select a texture and create a new image
instead of selecting an area and choosing a pattern.
- here the result is less random (since Fill resynthesized adds noise.)
Different from tiling since:
- seamless and irregular pattern

The continuum of randomness versus speed:
- Filters.Map.Tile is fast but has seams and regular pattern (even if you use "Make Seamless" first.)
- Filter.Render.Texture a seamless tile followed by tiling is seamless but still has regularity.
- Filte.Render.Texture an entire image is slower but seamless and moderately irregular.
- Edit.Fill with resynthesized pattern is slowest but seamless and highly irregular, unpatterned.

This is the first version.
There is a known bug: it doesn't work with Grayscale (I have submitted a bug to Bugzilla about a possible cause in Pygimp.)
Suggestions are welcome.

Standard installation for Python plugins.