lite-setup: configure lite-server test env
    
    Introduce a script that configures a local testing environment
    with ipa default.conf, krb5.conf, and ca.crt from a server hostname.
    
    The lite server configuration allows easy and convenient testing of
    IPA server and client code. It uses an existing 389-DS and KRB5 KDC
    server on another machine:
    
        $ contrib/lite-setup.py master.ipa.example
        $ source ~/.ipa/activate.sh
        (ipaenv) $ kinit username
        (ipaenv) $ make lite-server
    
    IPA server UI is available on http://localhost:8888/ipa/
    
    Signed-off-by: Christian Heimes <cheimes@redhat.com>
    Reviewed-By: Rob Crittenden <rcritten@redhat.com>