Remove the concept of a "right" sidebar
Remove the concept of a "right" sidebar

The naming of this was never appropriate and it isn't necessary to
populate this always. The "right" sidebar should only be rendered on the
output formats which require it.
unl/UNL_UCBCN_System,unl/UNL_UCBCN_System,unl/UNL_UCBCN_System,unl/UNL_UCBCN_System,unl/UNL_UCBCN_System