Fixes for: LP: #391105, #390405
  * debian/control: add screen-profiles and screen-profiles-extras
    transitional packages
  * debian/postinst, debian/prerm, debian/rules: fix screen-profiles ->
    byobu upgrades; drop byobu's attempt to remove the dpkg-divert on
    /usr/bin/screen, as this fails; establish links in the postinst,
    remove in the prerm
  * debian/screen-profiles.postinst: remove the diversion on *installation*
    of this transitional package


Signed-off-by: Dustin Kirkland <kirkland@canonical.com>