simplify code
fix refnanny error output in Py3
disable return value saving in finally clauses that only change the GIL status
fix C compiler warning about unused expression result

--HG--
extra : transplant_source : q%D5F8/%0B6%E2%B7R%F3%C9%E1%98%1B%E0X%A0%F1I
fix C compiler warning about unused expression result
merge 0.19.x branch into master
avoid redundant NULL inits for extension type fields in tp_new()
fix crash when looking up closure names in OptimizeBuiltinCalls transform (after running CreateClosureClasses transform)
fix constant folding of PrimaryCmpNode operands
optimise object.append() only when return value is not used and adapt signature accordingly
disable exception check for special C return type (always assume that it's an exception when -1 is returned)

--HG--
extra : amend_source : 88f30462a27faf52fcee83af0d1dce714e4f7e69
inline bytearray.append()
add integer fast-path to __Pyx_PyIndex_AsSsize_t()
fix doctest in Py3
move C declaration before code
Accept tuple for cythonized extension list.
Complex int division not well defined.

It's sensitive to compiler implementation.
Fix C++ complex for clang.
Add support for external C++ template functions.

The syntax follows that of template classes, namely

    cdef T foo[T](T, ...)
Add function template tests.