Add two tables to db scheme file

db_structure.xml

@@ -310,6 +310,102 @@
 
  </table>
 
+ <table>
+
+  <name>*dbprefix*principalgroups</name>
+
+  <declaration>
+
+   <field>
+    <name>id</name>
+    <type>integer</type>
+    <default>0</default>
+    <notnull>true</notnull>
+    <autoincrement>1</autoincrement>
+    <unsigned>true</unsigned>
+    <length>4</length>
+   </field>
+
+   <field>
+    <name>principal_id</name>
+    <type>integer</type>
+    <default></default>
+    <notnull>true</notnull>
+    <unsigned>true</unsigned>
+    <length>4</length>
+   </field>
+
+   <field>
+    <name>member_id</name>
+    <type>integer</type>
+    <default></default>
+    <notnull>true</notnull>
+    <unsigned>true</unsigned>
+    <length>4</length>
+   </field>
+
+   <index>
+    <name>principals_members_index</name>
+    <unique>true</unique>
+    <field>
+     <name>principal_id</name>
+     <sorting>ascending</sorting>
+    </field>
+    <field>
+     <name>member_id</name>
+     <sorting>ascending</sorting>
+    </field>
+   </index>
+
+  </declaration>
+
+ </table>
+
+ <table>
+
+  <name>*dbprefix*principals</name>
+
+  <declaration>
+
+   <field>
+    <name>id</name>
+    <type>integer</type>
+    <default>0</default>
+    <notnull>true</notnull>
+    <autoincrement>1</autoincrement>
+    <unsigned>true</unsigned>
+    <length>4</length>
+   </field>
+
+   <field>
+    <name>uri</name>
+    <type>text</type>
+    <default></default>
+    <notnull>false</notnull>
+    <length>255</length>
+   </field>
+
+   <field>
+    <name>displayname</name>
+    <type>text</type>
+    <default></default>
+    <notnull>false</notnull>
+    <length>255</length>
+   </field>
+
+   <index>
+    <name>uri</name>
+    <unique>true</unique>
+    <field>
+     <name>uri</name>
+     <sorting>ascending</sorting>
+    </field>
+   </index>
+
+  </declaration>
+
+ </table>
+ 
  <table>
 
   <name>*dbprefix*properties</name>