make Makefile more friendly for debian packaging (no functional changes)
make Makefile more friendly for debian packaging (no functional changes)

beni55/disco,ErikDubbelboer/disco,ErikDubbelboer/disco,pombredanne/disco,ErikDubbelboer/disco,oldmantaiter/disco,oldmantaiter/disco,seabirdzh/disco,simudream/disco,ktkt2009/disco,mwilliams3/disco,seabirdzh/disco,pombredanne/disco,discoproject/disco,beni55/disco,seabirdzh/disco,pavlobaron/disco_playground,discoproject/disco,scrapinghub/disco,pombredanne/disco,discoproject/disco,discoproject/disco,pavlobaron/disco_playground,pavlobaron/disco_playground,pooya/disco,beni55/disco,mozilla/disco,ktkt2009/disco,pooya/disco,simudream/disco,pavlobaron/disco_playground,simudream/disco,mozilla/disco,ErikDubbelboer/disco,ktkt2009/disco,mwilliams3/disco,pombredanne/disco,beni55/disco,pooya/disco,mozilla/disco,oldmantaiter/disco,ktkt2009/disco,discoproject/disco,simudream/disco,pombredanne/disco,scrapinghub/disco,beni55/disco,mwilliams3/disco,oldmantaiter/disco,scrapinghub/disco,seabirdzh/disco,mwilliams3/disco,oldmantaiter/disco,mozilla/disco,ktkt2009/disco,scrapinghub/disco,pooya/disco,seabirdzh/disco,simudream/disco,ErikDubbelboer/disco,mwilliams3/disco