FS-7966: multiple fixes for msvc 2015 build, silence multiple warnings

libs/broadvoice/src/libbroadvoice.2015.vcxproj

@@ -202,7 +202,6 @@
     <ClInclude Include="broadvoice\broadvoice.h" />
     <ClInclude Include="broadvoice\version.h" />
     <ClInclude Include="broadvoice\private\broadvoice.h" />
-    <ClInclude Include="broadvoice.h" />
   </ItemGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
   <ImportGroup Label="ExtensionTargets">

libs/broadvoice/src/msvc/inttypes.h

@@ -59,6 +59,8 @@ typedef __int64		int64_t;
 #define strcasecmp _stricmp
 #if _MSC_VER < 1900
 #define snprintf _snprintf
+#else
+#include <math.h>
 #endif
 
 #if !defined(INFINITY)