Make Heat's non_empty_stack usable without a server

We don't really need to test with a server to check Heat's
API responses. So just use a trivial resource type (a LaunchConfig)
to create some objects that we can query against. Now we can use
this test to gate.

Change-Id: I71bc065d8a1d2064ca90406543a376ce4d477275
Fix failures when l3_agent_scheduler ext is not available

Some plugins do not support the L3 agent scheduler extension.
Therefore, make the tests that rely on it dependent on whether
this is actually available in the plugin under test.

Change-Id: I3154b646677379a34465c6826b71d4ad72c471a2
Closes-bug: #1231152
Refactor network client

This patch implements the following steps in network client refactoring
1) Automatically 'generated' list_, show_, delete_ methods for most of
the resources
2) XML and JSon client implementations inherit common base
3) Every list method now supports filters

This change allow to remove existing list_, show_ and delete_ methods for
simple resources from both clients.

Some tests were fixed to simplify mapping between client method name and
resulting URI (example: list_floatingips instead of list_floating_ips)

Change-Id: I0eb46f8e3d90809dbfc54d4a250cd6aecfdc2c3b
SSH connection related cleanups

Catching only the SSHException the AuthenticationException is
 a subclass of the SSHException in the ssh.py.

test_connection_auth method changed to exception raiser method, in order
to avid unwanted catch-and-raise-new-exception code from the
RemoteClient.

Use similar ssh connectivity check with the test_network_basic_ops,
as with all other test cases, so using the implicit
connection validation of the RemoteClient.

Improve ssh connection logging by logging the reason of the connection
failure.

Change-Id: Ia2599f7f2c2fdc6fcbf7ad3337d82adcc50e4d16
scenario cross_tenant_connectivity

test conectivity between VMs in the same tenant and on different
tenants.
for each case, test that default state blocks traffic(*), that security
rules allow only specified traffic

(*)negative connectivity check is skipped until bug 1252620 is fixed
   TODO(yfried): enable them once bug is fixed

Also adds workaround for bug 1247568 in python-neutronclient (preventing
tearDownClass from ignoring deleted neutron resources

Change-Id: I212873d46e20ff3161e376105af18020b1cf1c9d
Merge "SSH connection related cleanups"
Merge "Make Heat's non_empty_stack usable without a server"
Merge "Refactor network client"
Merge "scenario cross_tenant_connectivity"
Merge "Fix failures when l3_agent_scheduler ext is not available"