PatchSet doesn't support raw bytes

[weihanglo]

In 3545dae, the current PatchSet::parse only support UTF-8 input but raw bytes. This was an oversight I forgot to fix when implementing it.

diffy/src/patch_set/parse.rs

Lines 58 to 68 in 3545dae

	pub fn parse(input: &'a str, opts: ParseOptions) -> Self {
	// Strip email preamble once at construction
	let input = strip_email_preamble(input);
	Self {
	input,
	offset: 0,
	opts,
	finished: false,
	found_any: false,
	}
	}

Since Patch already supports raw bytes parsing, PatchSet should follow.

[weihanglo]

Related #43