Wrap TextEdit cursor positions after trailing whitespace.

QTextDocument and therefore TextEdit doesn't wrap lines or the cursor position on trailing whitespace. This means that when entering whitespace characters the cursor position will not increase past the far edge of the TextEdit until a visible character is entered which triggers the creation of a new line. An option to QTextLayout which creates a new empty line at the end of a layout if white space wraps would allow the cursor to instead appear on a new line in this circumstance. It would however need to be selectively enabled to prevent unnecessary trailing lines in presentation uses of QTextDocument, and in all uses of QTextDocument there shouldn't be new lines introduced between text blocks.