Ticket 50439 - Update docker integration to work out of source directory
    
    Bug Description: Docker did not function in some cases, and we had to wait for
    releases via rpm.
    
    Fix Description: This adds the support to build from source into the tree
    so that we can build and test git master. This also resolves a var/run
    issue in the image, as well as some other minor python cleaning such
    as handling sigchld to act as init.
    
    https://pagure.io/389-ds-base/issue/50439
    
    Author: William Brown william@blackhats.net.au
    
    Review by: spichugi