[FIX] modules: Restore module pref errors display (lost in r48366 bootstrap integration)

git-svn-id: file:///var/local/code.tiki.org/tikisvn/branches/13.x@52413 b456876b-0849-0410-b77d-98878d47e9d5
[FIX] look & feel: Hide the Shadow Layer tab when not using the shadow layer layout (classic)

git-svn-id: file:///var/local/code.tiki.org/tikisvn/branches/13.x@52414 b456876b-0849-0410-b77d-98878d47e9d5