remove old RT 3.8 stuff and just keep RT 4.x Apache stuff

remove everything that was just used by the old RT 3.8 lighttpd setup

keep everything that is used by the new RT 4.x apache setup

it's files/rt/50-debconf in old, templates/rt/50-debconf.erb in new

role/request-trackers.pp isn't used anymore, neither is the lighttpd template

Change-Id: Iff9eeafa26889d0f2b123c6ddfb2e02e441042f3
Merge "remove old RT 3.8 stuff and just keep RT 4.x Apache stuff" into production