enable test_servers_negative

this was disabled when we were seeing flakey fails during Folsom
release, however all but one of these tests current pass. And the
failure is a new nova bug. Pushing to CI to verify that bug on both
databases before providing the fixes to nova (of which there will
be at least 2)

fix xml clients for negative tests

the xml clients were failing additional tests because the clients
didn't support all the features as the json tests. This enables
security_groups and networks in the xml client for create.

It also skips the test_create_numeric_server_name as that can't be
tested in xml, it always turns it into a string.

Fixes bug #1046870

Change-Id: I8a3a0bef9b1d134da369242a0cf14c3dcb61c6de
Adding test_delete_the_default_security_group negative test

In addition fixing few pep8 wrong identations.

Change-Id: Id645f3a8006639ba1e58b14856ac6720fc9b474d
Adding test_security_group_rules_create_with_invalid_port_range

A negative test which verifies that a Security Group rule creation
with invalid port range fails.

In addition, fixing few pep8's identation errors.

Change-Id: I092201fb33392a28de88c68e5cf4b86e2e748a84
Merge "enable test_servers_negative"
Merge "Adding test_security_group_rules_create_with_invalid_port_range"
Merge "Adding test_delete_the_default_security_group negative test"