add custom exception for unshare(2) failures
    change getLog().warn to getLog().warning for consistency
    fix namespace collision with python-mock [BZ# 601725]
    from Kirby Zhou <kirbyzhou@sogou-inc.com>
    remove rpmdb files before rebuilding SRPM [BZ# 719008]
    from Marko Myllynen <myllynen@redhat.com>
    integrate mock with RHN
    from Giam Teck Choon <choon@choon.net>
    add support for passing options to yum-buildep via mock cfg