[FIX] Switch Theme: Explain why the switch theme module doesn't work when using the default bootstrap "Theme selection"

git-svn-id: file:///var/local/code.tiki.org/tikisvn/branches/13.x@52415 b456876b-0849-0410-b77d-98878d47e9d5
[ENH] modules: Display an individual module_error as an error

git-svn-id: file:///var/local/code.tiki.org/tikisvn/branches/13.x@52416 b456876b-0849-0410-b77d-98878d47e9d5