Draft: windows fixes

make possible to comple kwiver on windows.

tested with

CMAKE_BUILD_TYPE Release
KWIVER_ENABLE_ARROWS ON
KWIVER_ENABLE_C_BINDINGS ON
KWIVER_ENABLE_PYTHON = ON
KWIVER_ENABLE_FFMPEG = ON
KWIVER_ENABLE_MVG = ON
KWIVER_ENABLE_KLV = ON
KWIVER_ENABLE_OPENCV = ON

and every other arrow off

depends on !60 (merged)