single threaded for profile-installed.py
using skip known bad
Use PySequence_Fast* to iterate over the list

Pre commit:

$ NOSE_PROCESSES=0 PILLOW_RUN_KNOWN_BAD=1 time ./test-installed.py Tests/test_image_point.py
..
----------------------------------------------------------------------
Ran 2 tests in 132.056s

OK
131.63user 0.62system 2:12.28elapsed 99%CPU (0avgtext+0avgdata 292176maxresident)k
264inputs+0outputs (2major+451088minor)pagefaults 0swaps

Post:

$ NOSE_PROCESSES=0 PILLOW_RUN_KNOWN_BAD=1 time ./test-installed.py Tests/test_image_point.py
..
----------------------------------------------------------------------
Ran 2 tests in 0.338s

OK
0.52user 0.06system 0:00.59elapsed 98%CPU (0avgtext+0avgdata 257584maxresident)k
176inputs+32outputs (2major+18033minor)pagefaults 0swaps

$ python --version
Python 2.7.6 (2.3.1+dfsg-1~ppa1, Jun 20 2014, 09:27:47)
[PyPy 2.3.1 with GCC 4.6.3]
DRY, moved case inside loop
pypy performance test
Use PySequence_Fast for Image.putdata

Pre-Commit:

$ NOSE_PROCESSES=0 time ./test-installed.py Tests/test_image_putdata.py
...
----------------------------------------------------------------------
Ran 3 tests in 131.623s

OK
131.77user 0.18system 2:14.04elapsed 98%CPU (0avgtext+0avgdata 325632maxresident)k
87376inputs+8outputs (314major+47333minor)pagefaults 0swaps

Post:

$ NOSE_PROCESSES=0 time ./test-installed.py Tests/test_image_putdata.py
...
----------------------------------------------------------------------
Ran 3 tests in 0.534s

OK
0.77user 0.05system 0:00.83elapsed 99%CPU (0avgtext+0avgdata 296352maxresident)k
0inputs+0outputs (0major+21462minor)pagefaults 0swaps
enable test_16bit_lut on pypy
2.8 million pyaccesses take a while, nomatter what
Image.point tests for Float LUT
Mode F and I tests for Image.putdata
Merge pull request #821 from wiredfool/pypy-performance

PyPy performance improvements
Update CHANGES.rst [CI skip]
Merge remote-tracking branch 'upstream/master' into pypy3_performance