New lines not stored properly in permalink/diff

If there are any new lines in the left side (`oldText`), they are removed when you hit 'Diff.'

It seems like whitespace/newlines are stripped from every line, both in permalink & diff. For instance, if you type the same thing on both sides, but insert random newlines, it will show that you deleted the whitespace adjacent to the newlines. And newlines aren't preserved in permalinks.