Added #include <ert/util/util.h> to type_macros + changed abort message.
Added fwd_step_enkf.h to the list of installed headers.
Explicitly added #include <ert/util/type_macros.h>
Added COMPILER_GCC as default defined symbol for ert_module
Merge pull request #525 from joakim-hove/ert_module_update

Ert module update