Removed trailing white spaces

Removed trailing whitespaces with

```sh
for file in `grep -r " $" * | cut -d : -f 1 | sort | uniq | grep -v " "`; do sed -i 's/[ \t]*$//' $file; done
```

and some handwork.

templates/repo/single_file.tmpl

@@ -21,7 +21,7 @@
         </div>
         {{end}}
     </div>
-    
+
     {{if not .FileIsText}}
     <div class="panel-body file-body file-code code-view">
         {{if .IsImageFile}}