Avoid wikifying system tiddlers

Fixes #2814

core/ui/ViewTemplate/body.tid

@@ -1,16 +1,24 @@
 title: $:/core/ui/ViewTemplate/body
 tags: $:/tags/ViewTemplate
 
+\define re() ^\$\:\/([^/])*$
+
 <$reveal tag="div" class="tc-tiddler-body" type="nomatch" state=<<folded-state>> text="hide" retain="yes" animate="yes">
 
-<$list filter="[all[current]!has[plugin-type]!field:hide-body[yes]]">
+<$list filter="[all[current]is[missing]!is[shadow]]" template="$:/language/MissingTiddler/Hint" emptyMessage="""
 
-<$transclude>
+<$list filter="[all[current]!is[system]] [all[current]tag[$:/tags/Image]] [all[current]regexp<re>] +[!has[plugin-type]!field:hide-body[yes]]">
 
-<$transclude tiddler="$:/language/MissingTiddler/Hint"/>
-
-</$transclude>
+<$transclude/>
 
 </$list>
 
+<$list filter="[all[current]is[system]] -[all[current]tag[$:/tags/Image]] -[all[current]regexp<re>] +[!has[plugin-type]!field:hide-body[yes]]">
+
+<$codeblock code={{!!text}} language={{!!type}}/>
+
+</$list>
+
+"""/>
+
 </$reveal>