[CMake] Add suppport for new IDE

[forumer at smartmobili.com]

Hi,

I would like to add some support for generating makefiles/IDE solutions 
for the D language (http://dlang.org).
Especially I would like to be able to generate VisualD and monoD 
projects.
The language is hold inside files with a .d extension and that can be 
compiled by 3 differents compilers:

1)dmd: the official compiler
2)gdc: compiler based on gcc
3)ldc: compiler based on llvm


There is already a kind of makefile system called dub that build 
libraries/application but it cannot generate ide projects.
So in a perfect world it would be cool to add support for dub makefile, 
VisualD and MonoD.

Is there any example about how to do that ?
Do you support other languages except C/C++ ?



Thanks