Added request and response for post. Load only id on sync request

docs/samples/request_post.xml

@@ -0,0 +1,12 b''
+<request>
+    <version>
+        <protocol>1</protocol>
+        <models>
+            <post>1</post>
+        </models>
+    </version>
+    <data>
+        <id>id1/1</id>
+        <id>id2/56</id>
+    </data>
+</request>

docs/samples/response_post.xml

@@ -0,0 +1,31 b''
+<response>
+    <status>success</status>
+    <models>
+        <post>
+            <id>id1/1</id>
+            <title>13</title>
+            <text>Thirteen</text>
+            <thread>id1/12</thread>
+            <pub-time>12</pub-time>
+            <edit-time>13</edit-time>
+            <previous-id>id1/3,id23/5</previous-id>
+            <after-id>id2/3,id43/5</after-id>
+        </post>
+        <post>
+            <id>id1/2</id>
+            <title>13</title>
+            <text>Thirteen</text>
+            <pub-time>12</pub-time>
+            <edit-time>13</edit-time>
+            <tags>
+                <tag>tag1</tag>
+            </tags>
+        </post>
+        <post>
+            <id>id2/1</id>
+        </post>
+        <post>
+            <id>id2/5</id>
+        </post>
+    </models>
+</response>

docs/samples/request_sync.xml

@@ -1,28 +1,26 b''
 <?xml version="1.1" encoding="UTF-8" ?>
 <request>
     <version>
         <protocol>1</protocol>
         <models>
             <post>1</post>
         </models>
     </version>
     <data>
         <type>pull</type>
         <timestamp>0</timestamp>
         <hosts>
             <allow>
                 <host>*</host>
             </allow>
             <deny></deny>
             <pools>
                 <pool>test1</pool>
                 <pool>test2</pool>
             </pools>
             <tags>
                 <tag>tag1</tag>
             </tags>
         </hosts>
-        <!-- Get only posts id to load posts later (maybe from several hosts) -->
-        <id-only>true</id-only>
     </data>
 </request>

docs/samples/response_sync.xml

@@ -1,32 +1,18 b''
 <?xml version="1.1" encoding="UTF-8" ?>
 <response>
     <status>success</status>
     <models>
         <post>
             <id>id1/1</id>
-            <title>13</title>
-            <text>Thirteen</text>
-            <thread>id1/12</thread>
-            <pub-time>12</pub-time>
-            <edit-time>13</edit-time>
-            <previous-id>id1/3,id23/5</previous-id>
-            <after-id>id2/3,id43/5</after-id>
         </post>
         <post>
             <id>id1/2</id>
-            <title>13</title>
-            <text>Thirteen</text>
-            <pub-time>12</pub-time>
-            <edit-time>13</edit-time>
-            <tags>
-                <tag>tag1</tag>
-            </tags>
         </post>
         <post>
             <id>id2/1</id>
         </post>
         <post>
             <id>id2/5</id>
         </post>
     </models>
 </response>