Add JSON validation to update view

JSON validation has now been added to the update view following the same format
as create. Since 'valueDecoded' does not have the ability to check if the value
is base64 before decoding then this must be checked first; if it is base64 then
use the decoded one, if not just get the value.

Change incorrect trailing span close to label.

ui/index.html

@@ -252,7 +252,7 @@
 
                   <button {{ action "createKey"}} {{bind-attr disabled=newKey.isInvalid }} {{ bind-attr class=":btn newKey.isValid:btn-success:btn-default" }}>Create</button>
                   {{#unless newKey.isFolder }}
-                  <label class="form-checkbox">{{ input type=checkbox checked=newKey.validateJson }}Validate JSON</span>
+                  <label class="form-checkbox">{{ input type=checkbox checked=newKey.validateJson }}Validate JSON</label>
                   {{/unless}}
                   <button {{ action "deleteFolder"}} {{ bind-attr class=":btn :pull-right isLoading:btn-warning:btn-danger isRoot:hidden" }}>Delete folder</button>
                 </form>
@@ -310,11 +310,12 @@
                 {{errorMessage}}
               </div>
               <form class="form">
-                <div class="form-group">
+                <div {{ bind-attr class=":form-group model.validateJson:validate model.isValidJson:success:error" }}>
                   {{ textarea value=model.valueDecoded class="form-control" disabled=model.isLocked}}
                 </div>
                 <button {{action "updateKey"}} {{bind-attr disabled=isLoading}} {{bind-attr class=":btn isLoading:btn-warning:btn-success"}} {{bind-attr disabled=isLocked}}>Update</button>
                 <button {{action "cancelEdit"}} {{bind-attr disabled=isLoading}} {{bind-attr class=":btn isLoading:btn-warning:btn-default"}}>Cancel</button>
+                <label class="form-checkbox">{{ input type=checkbox checked=model.validateJson }}Validate JSON</label>
                 <button {{action "deleteKey"}} {{bind-attr disabled=isLoading}} {{bind-attr class=":btn :pull-right isLoading:btn-warning:btn-danger"}} {{bind-attr disabled=isLocked}}>Delete key</button>
               </form>
             </div>

ui/javascripts/app/models.js

@@ -195,8 +195,17 @@ App.Key = Ember.Object.extend(Ember.Validations.Mixin, {
 
   // Check if JSON is valid by attempting a native JSON parse
   isValidJson: function() {
+    var value;
+
     try {
-      JSON.parse(this.get('Value'));
+      window.atob(this.get('Value'));
+      value = this.get('valueDecoded');
+    } catch (e) {
+      value = this.get('Value');
+    }
+
+    try {
+      JSON.parse(value);
       return true;
     } catch (e) {
       return false;