Zone Export - some refactoring and new test case to scenario test suite

1) test_all_recordset_types_exist_in_show_zonefile
   Verifies: "All zone's recordsets (vary of types
	      and number of records) presents in
	      the zonefile export"
2) Refactoring the existing tests by adding "wait_until"
   that wasn't in use.

Change-Id: I6b657ef83f04a84526ca7ba29a5b7d0d756402f0
1 file changed