All of the remaining includes of boost/bind.hpp may be removed from
slideshow, as last remaining uses of boost::bind have been removed from
the module. There should be no side effects due to this change.

Change-Id: I4e1855545fad69d09e594d0be139c09aad561b2d
Reviewed-on: https://gerrit.libreoffice.org/19395Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Noel Grandin <noelgrandin@gmail.com>