FYI: CMake Portgroup enhancement: use a custom CMAKE_BUILD_TYPE

[René J.V. Bertin]

The cmake PortGroup could use some attention to improve the way MacPorts' mechanism for controlling build (compiler, linker) options interacts with cmake's mechanism.

http://trac.macports.org/ticket/49108

My proposed change currently attached to that ticket turns out to be incomplete (http://trac.macports.org/ticket/49108#comment:3). Getting the originally intended effect where I want(ed) it is easy enough, but there is at least one other aspect (that was already pending) that could be taken into account : the preprocessor options. That's the reason I'm advertising the ticket here.

R.