- Update to 0.5.3.
    - Fix double free in pk-gstreamer-install which causes a crash. Fixes
        #526600
    - Exit pk-command-not-found with 127 when we have not run a program. Fixes
        #527044
    - Fix crash in notification daemon under some conditions due to
        non-resident GTK module.
    - Don't explicitly download the file lists when using pk-command-not-found