Working version for Windows

[Ashafix]

Changes

• __attribute__((visibility("default"))) was replaced to make non GNU compiler accept the file
• in order to make it work on Windows fmemopen and open_memstream were replaced with Windows specific functions. CreateFileA should only create in-memory files unless the files become too big.
• the biggest apparent change is due to if ((fin != NULL) && (fout != NULL)) became if ((fin == NULL) || (fout == NULL)) to get rid of one level of indentation and the else block. This doesn't change any of the code or logic.
• whitespace: cleanup

Testing

1. Ubuntu

• Compiles and runs on Ubuntu 16.04 LTS with Python 2.7 and 3.5, no apparent change in the run time for the unit tests

2. Windows 10

• Python 2.5: using Microsoft Visual C++ Compiler for Python 2.7
• Python 3.5: using Visual Studio 2015
• Python 3.7: using Visual Studio 2015

Run times

1. Ubuntu laptop (i5-2520M, 2.50 GHz)

• Python 2.7: ~20 msec for 24 tests
• Python 3.5: ~25 msec for 24 tests

2. Windows (i5-2500, 3.30 GHz)

• Python 2.7: ~125 msec for 24 tests
• Python 3.5: ~120 msec for 24 tests
• Python 3.7: ~120 msec for 24 tests

Tests were run with python -m unittest discover

[shyuep]

Many thanks!