nvda

838973ba - Switch to building with Visual Studio 2015. This is mandatory; no other version will work.

Switch to building with Visual Studio 2015. This is mandatory; no other version will work. * Upgrade to Scons 2.4.1 providing support for VC2015 * Ignore warning c4091: unnamed typedef enums (in Windows SDK 7.1a dbghelp.h). * fix warnings c4302, c4311, and c4312 (trunkation or extending when casting from a 32 bit type to a 64 bit type or the other way around): * VBuf docHandles are now unsigned longs instead of ints. * Replace all explicit casts from unsigned long to handles (HANDLE, HWND) with UlongToHandle. * Replace all explicit casts from handles (HANDLE, HWND) to unsigned long with HandleToUlong. * MSHTML vbufBackend: fix syntax of string concatination with a define to be compatibal with VC2015. Strings can now have a suffix letter, thus two strings that should be joined must now contain a space between them. Fixes #5592.