Add a utility to validate config (lsedlar)
    
    - [variants] Stop printing stuff to stderr unconditionally (lsedlar)
    - Fix atomic/ostree config validations (lsedlar)
    - [pungi-wrapper] Remove duplicated code (lsedlar)
    - [checks] Add a check for too restrictive umask (lsedlar)
    - [util] Remove umask manipulation from makedirs (lsedlar)
    - Filter variants and architectures (lsedlar)
    - Refactor checking for failable deliverables (lsedlar)
    - [buildinstall] Do not crash on failure (lsedlar)
    
    Signed-off-by: Dennis Gilmore <dennis@ausil.us>