Boost Polygon unmaintained

Hi,

The Boost Polygon library seems unmaintained. [https://github.com/boostorg/polygon/pull/74](This fix) should quite clearly not introduce a regression and fixes an essential bug in the library.

It would be great if someone could take over and at least include basic fixes. There's also tons of garbage unused functions in Boost Polygon (for example `testTrapezoidArbitraryFormationSelfTouch1`) that write to `stdout` and should probably be unit tests somewhere, but in the current form make no sense and only slow down compilation. Removing all this cruft would probably also be a great addition.

Thanks!