prototypes for extending dpkg script functionailities
returns a list of packages with open vulnerabilities, corresponding CVE-# and description. May return more than one hit per package as packages may be vulnerable for multiple reasons. Does not (yet) list packages with fixed vulnerabilites. Beware, it is probably full of bugs.
returns a list of packages which no other installed package depends on. This consitutes a "leaf" as opposed to a "node" in the package tree.