In order to add a package, do the following:

(1) Pick a name for your package (we will use 'foo' here)

(2) Create a directory, put the efun definition in foo/foo.spec.  If your code needs to export
    additional symbols for the rest driver code, create a foo/foo.h for automatic inclusion.

(3) implement the efuns in "foo.cc", you can have multiple source file if needed.

(4) Write CMakeLists.txt for this package, look at examples in other packages. make sure to either provide
    option(PACKAGE_FOO, "foo package", ON) or set (PACAKGE_FOO ON), make sure you also define an target named
    "package_foo". adding custom compile flags and link libraries there.

(5) Run cmake from top dir and if your package is set to ON it should be automatically built and linked.