Merge topic 'msvc2015-support'

15ca5221 vtkWin32OpenGLRenderWindow: static_cast to BYTE
5367d9cc vtkWin32OpenGLRenderWindow: fix some whitespace
d16dca59 vtkFreeTypeTools: use vtkIdType for cache ids
033b8498 msvc2015: fix narrowing warnings
a4cf06de hdf5: fix long long format detection
71894112 hdf5: detect %I64d specifier
385e0e76 vtkEnSightReader: refactor a call
f2f35036 vtkhdf5: don't expect timezone with VS2015
...

Acked-by: Kitware Robot <kwrobot@kitware.com>
Merge-request: !446