AttributedString::set_text_color uses range end as a length

[mndstrmr]

In AttributedString::set_text_color and AttributedString::set_font, range.end is used as the length field to CFRange::init, which unless I am mistaken seems wrong to me.

The documentation implies that if I set the set range 3..4 to red, I would change only character 3 to be red, not 3 through 6, which is what currently happens.

The relevant code is here:

cacao/src/text/attributed_string.rs

Lines 45 to 58 in 7ffe398

	/// Sets the text (foreground) color for the specified range.
	pub fn set_text_color<C: AsRef<Color>>(&mut self, color: C, range: Range<isize>) {
	let color: id = color.as_ref().into();
	let range = CFRange::init(range.start, range.end);
	unsafe {
	let _: () = msg_send![
	&*self.0,
	addAttribute: NSForegroundColorAttributeName,
	value: color,
	range: range,
	];
	}
	}

[ryanmcgrath]

which unless I am mistaken

I do not believe you are. :)

A PR is welcome, otherwise I'll get to it in the next batch of fixes once I find the time. Thanks for the callout!