Return -1 if package is not installed or dependency not satisfied.
Return 0 if same version required is already installed.
Return 1 if installed version is greater than required.
--HG--
extra : convert_revision : 359b79cbe809e1818fe999dc1d55da7e635dbe44
New changes include a modified algorithm of the previous one, which
finally does not fail even with multiple repos, YAY!
Fixed some leaks as well, thanks to valgrind.
--HG--
extra : convert_revision : 3cffe1e9e9e9f7abf225ca3c6643377fc12a94bd
This algorithm works for all packages currently usable on xbps.
Previous code didn't take into account the correct order between
indirect and direct deps.
--HG--
extra : convert_revision : c49a20ce300e6e9dfa565325b40745b5a78b78ed