Tested that it builds with:
gcc 6.1.1, STATIC=OFF,i686
gcc 6.1.1, STATIC=OFF,armv7h
clang 3.8, STATIC=OFF,i686
clang 3.8, STATIC=OFF,armv7h
gcc 6.1.1, STATIC=ON,i686
clang 3.8, STATIC=ON,i686
Also tested that stack trace is generated fine on exception on:
i686, gcc 6.1.1, STATIC=OFF
(didn't bother testing all the other platforms/configs)
This should fix the build problem on OSX (#871, #901), but
I don't have OSX, so I could only test Clang on Linux.
The former was a faulty "fix" for gmtime_r not existing on Windows. The latter is needed only for dynamic builds, and is not included with msys2, which ends up fine because Windows is only built static at this time.