Carve proved it's a way to go, so the time have came to get rid of old
boolean operation module which isn't used anymore.
Still kept BOP interface but move it to BSP module. At some point it
could be cleaned up further (like perhaps removed extra abstraction
level or so) but would be nice to combine such a refactor with making
BSP aware of NGons.
Tested on linux using both cmake and scons, possible regressions on
windows/osx. Would check windoes build just after commit.
- only show mingw option when building with mingw
- always run cmake configure with convenience build targets so failed configurations stop re-configuring.
- disable WITH_GHOST_XDND in 'make lite'