Make and CMake support

These changes allow the selection of a build system different from XCode for clang analyzer.
The currently supported (but quite basic) options allow using CMake, Makefile and automake (configure must be available) based projects.

What should be changed:
* The workspace, target, ... fields should be named (and only shown) for the selected build toolchain.
* Currently it is not possible to add arguments for ```configure``` 
* CMake backend requires out of tree build, or the regeneration of CMake specific files may fail, if the toolchain changed.