Use defines from OTP's EPMD code instead of hardcoded vals

Signed-off-by: Peter Lemenkov <lemenkov@gmail.com>
Relax sd_notify hard requirement

Signed-off-by: Peter Lemenkov <lemenkov@gmail.com>
Merge branch 'use_otp_erl_epmd'

Conflicts:
	src/erlpmd.erl