Updated request and response samples to the simplier model definitions

docs/samples/request_get.xml

@@ -1,8 +1,7 b''
 <?xml version="1.1" encoding="UTF-8" ?>
 <request version="1.0" type="get">
-    <model>post</model>
-    <filter>
+    <model version="1.0" name="post">
         <id>id1/1</id>
         <id>id2/56</id>
-    </filter>
+    </model>
 </request>

docs/samples/request_pull.xml

@@ -1,8 +1,6 b''
 <?xml version="1.1" encoding="UTF-8" ?>
 <request version="1.0" type="pull">
-    <model>post</model>
-    <filter>
-        <version>3</version>
+    <model version="1.0" name="post">
         <timestamp_from>0</timestamp_from>
         <timestamp_to>0</timestamp_to>
         <tags>
@@ -15,5 +13,5 b''
             </allow>
             <!-- There can be only allow block (all other are denied) or deny block (all other are allowed) -->
         </sender>
-    </filter>
+    </model>
 </request>

docs/samples/response_get.xml

@@ -2,7 +2,7 b''
 <response>
     <status>success</status>
     <models>
-        <post>
+        <model name="post">
             <id>id1/1</id>
             <title>13</title>
             <text>Thirteen</text>
@@ -11,8 +11,8 b''
             <edit-time>13</edit-time>
             <previous-id>id1/3,id23/5</previous-id>
             <after-id>id2/3,id43/5</after-id>
-        </post>
-        <post>
+        </model>
+        <model name="post">
             <id>id1/2</id>
             <title>13</title>
             <text>Thirteen</text>
@@ -21,12 +21,6 b''
             <tags>
                 <tag>tag1</tag>
             </tags>
-        </post>
-        <post>
-            <id>id2/1</id>
-        </post>
-        <post>
-            <id>id2/5</id>
-        </post>
+        </model>
     </models>
 </response>