Add gnulib modules which make sense and remove few. The stuff gnulib
takes care can be dropped from configure.am.
Signed-off-by: Sami Kerola <kerolasa@iki.fi>
This will mean better portability, and a good reason to get rid of
various portability autotools directives which where part of this
project.
Signed-off-by: Sami Kerola <kerolasa@iki.fi>
