Better check for Debian-style distribution
Better check for Debian-style distribution

Check for '/var/lib/dpkg/status', not just '/var/lib/dpkg' (reported by
Markus Rathgeb).

HoMeCracKeR/0install,fdopen/0install,gasche/0install,afb/0install,bastianeicher/0install,timdiels/zeroinstall,gfxmonk/0install,DarkGreising/0install,dabrahams/0install,bhilton/0install,gasche/0install,fdopen/0install,timdiels/0install,gfxmonk/0install,pombreda/0install,fdopen/0install,pombreda/0install,afb/0install,0install/0install,bartbes/0install,timdiels/zeroinstall,gasche/0install,0install/0install,bartbes/0install,gfxmonk/0install,dabrahams/0install,afb/0install,michel-slm/0install,timdiels/0install,dabrahams/zeroinstall,bartbes/0install,HoMeCracKeR/0install,michel-slm/0install,dabrahams/zeroinstall,bastianeicher/0install,jaychoo/0install,dabrahams/zeroinstall,DarkGreising/0install,bhilton/0install,dabrahams/0install,jaychoo/0install,timdiels/zeroinstall,michel-slm/0install,dbenamy/0install,dbenamy/0install,0install/0install,timdiels/0install,pombreda/0install,bhilton/0install,DarkGreising/0install,HoMeCracKeR/0install,timdiels/0install,afb/0install,gasche/0install,dbenamy/0install,jaychoo/0install,bastianeicher/0install