project-dependant build system

I would like the build system to be configurable on a per-project basis.  I find it somewhat of a pain to use the current build system setup, because I like to put mu cmake-generated makefiles in <project_dir>/build directory, which means that I also have to put another makefile in <project_dir> that just defers to that one, just so that Sublime will be able to "find" it.