The generateCodeFrame function had the chance to infinite loop on windows machines due to how newline sequence lengths were being treated.
Newline sequence lengths were assumed to be a single character long which is not true on windows machines.

closes 3987

Fixed comment styling

Co-authored-by: Eduardo San Martin Morote <posva@users.noreply.github.com>

There were additional places that we needed to take line ending sequences into account to ensure that we placed  the ^^^s exactly where they should be.
Unix and Windows should now produce identical results.

Additionally, code was modified to handle source that is passed in that does not have a trailing newline character before the end of the source content.