spec: it should really follow guidelines
    
    * License is actually GPLv2+, not GPLv2
    * New packaging guidelines require to have python2 and python3 subpkgs
    * Usage of %python_provide macro
    * Drop unneded BR: pythonX-setuptools, we use distutils
    * Drop wron requires on python/python3, RPM requires python(abi) internally
    * Don't copy-paste sources 2 times for py2/py3 as it is pointless
    * Use %license tag for license
    * Use modern macroses like %pyX_build, %pyX_install
    * Run test-suite in %check
    * Drop obsolete %clean section
    * Define rpmfluff as %global
    
    Signed-off-by: Igor Gnatenko <ignatenko@redhat.com>