bd9a0ce pkgset: Create global repo in parallel to merging pkgsets

Authored and Committed by lsedlar 5 years ago
    pkgset: Create global repo in parallel to merging pkgsets
    
    The work in creating the repo is done in a separate process. This can
    easily use two threads.
    
    Signed-off-by: Lubomír Sedlář <lsedlar@redhat.com>