More test cases for disjoint

* Add a few more test cases, some of them related to the recent bug in the Cartesian segment-segment intersection strategy (see PR #175).
* Replace calls to `BOOST_CHECK` by calls to `BOOST_CHECK_MESSAGE`.
I don't understand this. There is hardly any difference between SEGMENT + dsv and just wkt...

I see the same implementation occurs in a lot of files. You can just use bg::wkt, which is streamable, and the whole pretty_print_geometry can be removed