Show message documentation to anon users

This was caused by the unexpected behavior of
$foo.append( undefined, $bar ); which did not append anything.

Arguably this is not wrong, since the documentation says that
it takes string, DOM and jQuery objects - still don't like it.

Took the easy way out by just hiding control buttons while
keeping the DOM structure the same.

Bug: 46159
Change-Id: If5dd662fd29d3dc63a4a49998dd698e448fbd8c6
Merge "Show message documentation to anon users"