let's see if the list order of the python releases makes a difference for the execution order in travis

extract some changes from pull request #504 that seem straight forward and helpful to speed up the travis builds

Update docs wrt property syntax deprecation

Allow passing define macros without specified values as commented directives

Add no_gc directive to fully disable GC

follow PEP492 change in Py3.5.2 that makes __aiter__() a simple function instead of an async function
See https://bugs.python.org/issue27243

numpy arrays are no longer omitted from locals()

Improve "missing cimport" message

Fix errors in example code sections in documentation.

Fix a typo in a comment

Fix mangling for C++ namespaced types

+ setup.py instructions for Visual C++ compiler

Add setup.py openMP instructions for Microsoft Visual C++ compiler

"ustring!s" (i.e. str(ustring)) is actually not safe to optimise away for f-string formatting in Py2 as it can fail to encode the Unicode string to a byte string. And it's unlikely to appear in practice.

Fix timestamps option to work when generating a C++ output file.