remove unused codes and add site'url configuration on admin

app/views/admin/setting/site_url.html

@@ -0,0 +1,51 @@
+{{template "admin/top.html" .}}
+<div class="m-b-md"> <h3 class="m-b-none">Site's URL</h3></div>
+
+<div class="row">
+
+<div class="col-sm-6">
+    <form id="add_user_form">
+        <section class="panel panel-default">
+            <div class="panel-body">
+                <div class="form-group">
+                    <label>Site's URL</label>
+                    <input type="text" class="form-control" name="siteUrl" value="{{.str.siteUrl}}" placeholder="http://localhost:9000">
+                    Please note that if the value isn't blank, it will override the "siteUrl" configuration on app.conf.
+                    <br>
+                    Site's URL will be used to upload images, find password, and send email...
+                </div>
+            </div>
+            
+            <footer class="panel-footer text-right bg-light lter">
+                <button type="submit" id="submit" class="btn btn-success btn-s-xs">Submit</button>
+            </footer>
+        </section>
+    </form>
+</div>
+
+</div>
+
+{{template "admin/footer.html" .}}
+<script src="/public/admin/js/jquery-validation-1.13.0/jquery.validate.js"></script>
+<script>
+$(function() {
+    init_validator("#add_user_form");
+    $("#submit").click(function(e){
+        e.preventDefault();
+        var t = this;
+        if($("#add_user_form").valid()) {
+            $(t).button('loading');
+            ajaxPost("/adminSetting/doSiteUrl", getFormJsonData("add_user_form"), function(ret){
+                $(t).button('reset');
+                if(!ret.Ok) {
+                    art.alert(ret.Msg);
+                } else {
+                    art.tips("Success");
+                }
+            });
+        }
+    });
+});
+</script>
+
+{{template "admin/end.html" .}}