Upgrade to build and run from VS2019

- New msvc142 directory (keeping with naming after version of C compiler)
- Added SDL2.lib/SDL2main.lib back in (compiled from SDL 2.0.8 source from libsdl.org)
- Post build step to copy SDL2.dll to debug directory

misc/msvc142/glsl_stringify.vbs

@@ -0,0 +1,18 @@
+Dim fso, infile, outfile, line
+Set fso = CreateObject("Scripting.FileSystemObject")
+Set infile = fso.OpenTextFile(WScript.Arguments(0))
+Set outfile = fso.CreateTextFile(WScript.Arguments(1), True)
+
+outfile.WriteLine("const char *fallbackShader_" & fso.GetBaseName(WScript.Arguments(0)) & " =")
+While Not infile.AtEndOfStream
+	line = infile.ReadLine
+	line = Replace(line, "\", "\\")
+	line = Replace(line, Chr(9), "\t")
+	line = Replace(line, Chr(34), "\" & chr(34))
+	line = Chr(34) & line & "\n" & Chr(34)
+	outfile.WriteLine(line)
+Wend
+outfile.WriteLine(";")
+
+infile.Close
+outfile.Close