The 3.0 series is an incremental improvement over the previous 2.8 series
despite the major version number change. A list of important changes is
available at http://www.cmake.org/cmake/help/v3.0/release/3.0.0.html

On the porting side
* The minimum FreeBSD release we have to support in the ports tree is now
  recent enough that ports/168671 can finally be committed: instead of
  building and using CMake's own copies of bzip2, curl, expat, libarchive,
  liblzma and zlib, we use the versions in ports and/or the base system.

* CMake's documentation system has been changed and vastly improved at the
  cost of now depending on Sphinx. We still generate only man pages, but can
  start generating the HTML documentation in the future if desired.

* devel/cmake-gui now uses Qt5 instead of Qt4 and does not needlessly build
  the ncurses UI that is installed by devel/cmake itself.

* CMake commit 3816cd2 fixes a longstanding issue in the detection of the
  Python interpreter and its libraries, but requires us to revert a
  workaround for that in Mk/Uses/python.mk itself, effectively reverting
  the patch introduced by ports/168159.

* Similarly, a few ports had to be fixed manually due to CMake being
  stricter when parsing some files or the ports detecting Python the wrong
  way. Fortunately, they all had been fixed upstream so I just grabbed the
  appropriate commits and pointed to them in the patches.
  science/gnudatalanguage had to have its PORTREVISION bumped because
  switching to USES=cmake:outsource removed a few files from the plist that
  were not supposed to have been installed in the first place.

PR:		168671
PR:		192644