Move the old luci.model.ipkg utility class into a separate package and
let the components using it depend on the new library package.
Signed-off-by: Jo-Philipp Wich <jo@mein.io>
* minor fix function _list() set to local
* new function compare_version() lua version of opkg compare-version
Signed-off-by: Christian Schoenebeck <christian.schoenebeck@gmail.com>