Add support for database extensions into the client

Allows creation of the extensions for the databases
diff --git a/postgresql/_database.sls b/postgresql/_database.sls
index b6ff3cc..dea37cb 100644
--- a/postgresql/_database.sls
+++ b/postgresql/_database.sls
@@ -39,6 +39,25 @@
     - user: root
     {%- endif %}
 
+{%- for name, extension in database.get('extension', {}).iteritems() %}
+postgresql_database_{{ svr_name|default('localhost') }}_{{ database_name }}_{{ name }}:
+  {%- if extension.get('enabled', true) %}
+  postgres_extension.present:
+    - schema: {{ extension.get('schema', 'public') }} 
+  {%- else %}
+  postgres_extension.absent:
+  {%- endif %}
+    - name: {{ name }}
+    - maintenance_db: {{ database_name }}
+    - user: root
+    {%- if admin is defined %}
+    {%- for k, p in admin.iteritems() %}
+    - db_{{ k }}: {{ p }}
+    {%- endfor %}
+    - user: root
+    {%- endif %}
+{%- endfor %}
+
 {%- if database.initial_data is defined %}
 
 {%- set engine = database.initial_data.get("engine", "backupninja") %}