Modernize, ditch 2to3

aksetup_helper.py

configure.py

contrib/fortran-to-opencl/translate.py

doc/conf.py

doc/make_constants.py

examples/benchmark.py

examples/demo-struct-reduce.py

examples/demo.py

examples/demo_array.py

examples/demo_elementwise.py

examples/demo_elementwise_complex.py

examples/demo_mandelbrot.py

examples/demo_meta_codepy.py

examples/demo_meta_template.py

examples/download-examples-from-wiki.py

examples/dump-performance.py

examples/dump-properties.py

examples/gl_interop_demo.py

examples/gl_particle_animation.py

examples/narray.py