Option for disabling the rendering of web link targets

This is a follow-up of issue #63. regarding the fact that web links are reported in the output PDF as a clickable label, followed by the full link target. This makes the result very ugly and being able to read the link on the paper-printed PDF is not very desirable nowadays, because people are usually fine with clicking them after reading on their PDF visualiser (the underlined label allows for that), or don't even print so often. Possibly, it might be useful an optional list of such link targets at the end of the document (or as foot page notes).

I've managed to remove such links by means of the custom CSS, yet a command line option (with the variants mentioned above) would be a nice addition.