makefile: Added make steps for generating release builds on Darwin
makefile: Added make steps for generating release builds on Darwin

Added release build steps for Darwin to the Makefile.

Now, can use just "make release" and "make release-to-resources" and it
will detect the OS currently being used.

apcera/kurma,apcera/kurma,apcera/kurma,apcera/kurma,apcera/kurma