Fix the non-defaults test failing to use UTF8

The non-default tests try to set UTF8 when UTF8 is not installed on the en_US
machine. These are non-default settings anyway, but one should presume the
correct locale should be set before this is attempted, this patch includes
that step.

In an ideal world we would use a locale module to do this.

This patch also fixes an Ubuntu 10.04 issue where you need to be absolute about
the locale and encoding as well.

Signed-off-by: Ken Barber <ken@bob.sh>
Merge pull request #194 from kbarber/fixed_failing_utf8_tests

Fix the non-defaults test failing to use UTF8
manage postgresql.conf entries
replace file_line resources by postgresql::pg_conf_entry
add reference to pgconf in fixtures.yaml
2.6 compatibility fix
Add pgconf module to spec helper.