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
This fixes all cases that previous code has with no changes...
sorry pancake.
--HG--
extra : convert_revision : 993d0aa060daf36d1b5ffa63725002dda122c091