debian package: decrease default cache size to 512MB
debian package: decrease default cache size to 512MB

kmike/splash,kod3r/splash,sunu/splash,pombredanne/splash,Youwotma/splash,dwdm/splash,pawelmhm/splash,Youwotma/splash,dwdm/splash,Youwotma/splash,pombredanne/splash,dwdm/splash,kod3r/splash,sunu/splash,pawelmhm/splash,kod3r/splash,kmike/splash,pombredanne/splash,sunu/splash,pawelmhm/splash,kmike/splash