add system test for named-checkconf -e

add system test for named-checkconf -e

Add a system test checking the command line switch -e of
named-checkconf. The test doesn't care about the whole output of the
effective configuration (in particular to avoid breaking the test for
each default statement that would change) but instead just ensure the
effective configuration is actually returned by checking the presence of
the _bind chaos builtin view as well a user provided view and option
change.