Add AUTOTYPE to DOSBox's programs

AUTOTYPE performs scripted keyboard entry into the running
DOS program.

It can be used to reliably skip intros, answer Q&A style questions
that some games ask on startup, or conduct a simple demo.

It allows for delaying input by any number of fractional seconds,
as well defining the pacing between keystrokes. It uses the
comma character "," to insert additional delays similar to modern
phone numbers.

It uses key_* names as defined by the mapper to avoid using SDL
scancodes[1], which are unstable across platforms. This approach
also allows the triggering of custom key bindings the use has
defined.

[1] https://wiki.libsdl.org/SDL_GetScancodeName

"Warning: The returned name is by design not stable across
platforms, e.g. the name for SDL_SCANCODE_LGUI is "Left GUI" under
Linux but "Left Windows" under Microsoft Windows, and some
scancodes like SDL_SCANCODE_NONUSBACKSLASH don't have any name at
all. There are even scancodes that share names, e.g.
SDL_SCANCODE_RETURN and SDL_SCANCODE_RETURN2 (both called
"Return"). This function is therefore unsuitable for creating a
stable cross-platform two-way mapping between strings and
scancodes."

.pvs-suppress

@@ -1,6 +1,14 @@
 {
     "version": 1,
     "warnings": [
+        {
+            "CodeCurrent": 432032057,
+            "CodeNext": 36027430,
+            "CodePrev": 0,
+            "ErrorCode": "V801",
+            "FileName": "sdl_mapper.cpp",
+            "Message": "Decreased performance. It is better to redefine the first function argument as a reference. Consider replacing 'const .. sequence' with 'const .. &sequence'."
+        },
         {
             "CodeCurrent": 4109900279,
             "CodeNext": 355817,