Rework pkg_audit to support pkg names without versions.
Fix audit utility.

- Now it accepts multiple patterns to check
- Pkg audit can also work with packages without version
- Fix bug with uniqueid hash table where unique id was not set [1]

Found by:	bapt
Print versions information in pkg-audit.
Do not assert if pattern is empty in query.

Return NULL iterator instead of asserting inside of libpkg.
Fix typo, pkg_static -> pkg-static

Reported by:	des