widget/reply: save raw message input before formatting

Prepare for upcoming conversion (errors) and possible debugging.

Restructure earlier posts:

	ALTER TABLE comments ADD raw text;
	UPDATE comments SET raw = regexp_replace(regexp_replace(raw,
		'<br />|<\/?p>', '', 'g'),
		E'\n?<img src="/thumb/640x(/.*)" />', E'\n\\1', 'g');