cmake: Define GLEW_STATIC only if we're linking with static GLEW library on Windows
cmake: Add "lib" prefix to static OSD library on Windows

This avoids name conflict with dynamic OSD library when compiling with MSVC.
cmake: Link the dynamic OSD library on Windows as well
cmake: Allow examples and regressions to dynamically link with OSD library
osd: Add OSD_API and OSD_TEMPLATE define for exporting symbols on Windows

Clients of the OSD library will need to define OSD_DLL if they want to
dynamically link against the OSD library.
cmake: Add OSD_DLL defines to examples and regressions
osd: Export some classes and methods for Windows DLL