Finish the info screen on visualise tool

[jstockwin]

You can pass show_info=True to the visualise tool, and this allows you to click on elements and see details etc.

It is unfinished and needs work.

• The visuals need improving -> we currently just throw loads of text into a figure. Perhaps this can be better formatted?
• Some of the fields could be improved, and we're missing e.g. character margins etc. It would be good if it enabled you to completely understand the LAParams, since these can be quite confusing.
• Additionally, once this is done it would be good to add an example to the documentation.