VIM crashes on :py import threading

What steps will reproduce the problem?
1. Compile vim on Windows with python2.7 support
2. Run :py import threading in gvim

What is the expected output? What do you see instead?
Expected: no output
Actual: VIM crashes, and `Fatal Python error: PyThreadState_Get: no current 
thread` is printed to console

What version of the product are you using? On what operating system?
7.4.781 on Windows (compiled with mingw64 with mingw64 Python 2.7 on MSYS2)

Original issue reported on code.google.com by beo...@gmail.com on 16 Jul 2015 at 10:08

1587 / vim

VIM crashes on :py import threading #384