Bug: Fix Surface.draw_texture's NinePatchTexture handling

[pushfoo]

Bug Report

Actual behavior:

arcade.gui.Surface.draw_texture has following incorrect behavior:

1. The check for angle uses x and y arguments
2. The check for alpha uses x and y arguments

arcade/arcade/gui/surface.py

Lines 100 to 110 in e76f345

	if isinstance(tex, NinePatchTexture):
	if x != 0 or y != 0:
	raise ValueError("Ninepatch does not support a position != (0,0) yet")
	if x != 0 or y != 0:
	raise ValueError("Ninepatch does not support a angle != 0 yet")
	if x != 0 or y != 0:
	raise ValueError("Ninepatch does not support a alpha != 255 yet")
	tex.draw_sized(size=(width, height))

Expected behavior:

1. The angle check uses the angle argument
2. The alpha check uses the alpha argument

[eruvanos]

Actually if the prepare_render() method is called, the viewport is changed, to limit rendering within bounds of the widget. Which means, a position on the NinePatchTexture would move it out of the viewport.

So in most situations setting position would break the draw function.

[pushfoo]

I've updated the ticket to reflect that. I still think we can make the correction as part of PyCon if someone is interested, but it may be a good idea to double check #1682 since there may have been a misunderstanding during its writing & review.