Blender Git Loki

C++ conformance fixes (MSVC /permissive-)

We (the Microsoft C++ team) use the Blender project as part of our "Real world code" tests.
I noticed a place in WIN32 specific code (dvpapi.cpp:85) where a string literal is losing
its const-ness when being passed to BLI_dynlib_open(). This is not permitted when using the
/permissive- conformance compiler switch (see our blog
https://blogs.msdn.microsoft.com/vcblog/2016/11/16/permissive-switch/)

My suggested fix is to add const and propagate it where needed. Another possible fix would be
to explicitly cast away the const.

Reviewers: mont29, sergey, LazyDodo

Subscribers: Blendify, sergey, mont29, LazyDodo

Tags: #platform:_windows

Differential Revision: https://developer.blender.org/D2495