postpone import of distutils Extension type in test runner in case setuptools gets imported in between

fix test runner and pyximport in Py 2.7.9 and 3.4+: setuptools replaces "distutils.dist.Distribution" *after* we import it, which then breaks the input validation in "distutils.cmd"

Minor cleanup (2.5 compat, mostly)

optimize general sorted(x) calls

fix shrinking and overflow in cpython.array

optimize sorted([a,b,c]) into PyList_Sort call

Emit DL_IMPORT macro for python3

--HG--
extra : transplant_source : %C6%5B%E6p%A8%07V%04%CC%8D%EB%12%BB%A2%87%B5%D3%9A%F0%60

--HG--
extra : transplant_source : %0Dr%DFY%8A%EF%F6%C1%9C/h%B5%23%CE3_%DCE%B2%03

implement PEP 479: replace accidental StopIteration exceptions that exit the generator body by RuntimeError

fix temp leak and crash when assigning a C value to both a Python and C target in a cascaded assignment

clean up regular expression in parser (not problematic as it only matches what the scanner already accepted)

cannot currently enable warning checks for C++ class definition syntax as there are incorrect warnings

extend C++ tests to make sure we do not generate warnings (and fix some warnings that we did generate)

tighten Python-to-C++-reference warning to apply only to C++ classes as target and do not show it by default (usage might be legitimate and/or enforced by an external API)