This patch makes erlware_commons easier to include as a dependency by
removing depedencies that are not needed at run time.
The top-level Makefile creates a .DEV_MODE marker file which is
detected by rebar.config.script. When the marker file is present, the
development only dependencies proper and neotoma are included and a
macro 'DEV_ONLY' is defined. The macro is used to only enable the
proper tests for development mode.
The ec_semver_parser.peg is now located in priv/ and is moved into
src/ by the Makefile. The generated ec_semver_parser.erl is now under
version control; it need not be rebuilt by all projects wishing to
include erlware_commons. It will be rebuilt, as before this change, on
every make invocation.
