Add compute personality feature config

Add personality config in compute-feature-enabled.
Remove using personality in general tests.
Add some tests to test_server_pesonality.
Change tests with personality to skip if disable.

Change-Id: Ieffa799949034b609b53c5c131d26bfe3cb83fa4
diff --git a/tempest/api/compute/servers/test_servers_negative.py b/tempest/api/compute/servers/test_servers_negative.py
index 6946be4..98b292a 100644
--- a/tempest/api/compute/servers/test_servers_negative.py
+++ b/tempest/api/compute/servers/test_servers_negative.py
@@ -66,6 +66,8 @@
 
     @test.attr(type=['negative'])
     @test.idempotent_id('b8a7235e-5246-4a8f-a08e-b34877c6586f')
+    @testtools.skipUnless(CONF.compute_feature_enabled.personality,
+                          'Nova personality feature disabled')
     def test_personality_file_contents_not_encoded(self):
         # Use an unencoded file when creating a server with personality