Rewrote prettyPrint to be much more flexible w/o loosing any functionality.

Now uses a helper method (makePrettyPrint) to generate the HTML. This can be called from anywhere and given an error stack to generate identical output compared to engine's error stack.

This also let us cleanup a lot of duplicate code in prettyPrint() itself and is much more maintainable now.
Merge branch 'master' of github.com:wvulibraries/engineAPI