Static build of patched QT for wkhtmltopdf and updated wkhtmltopdf

The new `wkhtmltopdf-qt` formula builds a static QT against the newest [wkhtmltopdf QT patched repository](https://github.com/wkhtmltopdf/qt).

The `wkhtmltopdf` formula URL is updated to the new [wkhtmltopdf repository](https://github.com/wkhtmltopdf/wkhtmltopdf). I've also added a new `--static` option to allow building against the `wkhtmltopdf-qt` formula.

I considered implementing the static QT build into the `wkhtmltopdf` formula, but didn't want users to have to rebuild the patched QT (which doesn't change very frequently) each time they needed to rebuild wkhtmltopdf (which will change more frequently, especially with [the work going to to revitalize the project](https://github.com/wkhtmltopdf/wkhtmltopdf/pull/34#issuecomment-32791780)).

I have tested both formulas on OS X 10.7 and 10.9. (Haven't had a chance to test on 10.8 yet, but as soon as I get it downloaded and a VM going I will).