sdl usage standards proposal 3:

again maintains fallbacks for folks that just don't want to use the lib (though if we do want to go that route, we'll likely want to re-review a few commits and put fallbacks, well, *back* at some point)
includes sdl in torqueconfig.h if in use to kill duplication.
adds a generic sdlPlatform.cpp for general methods, oneliners, and the like

Engine/source/platformX86UNIX/x86UNIXPlatform.cpp

@@ -1,5 +1,5 @@
 #include "platform/platform.h"
-
+#ifndef TORQUE_SDL
 bool Platform::openWebBrowser(const char* webAddress)
 {
    String startingURL(webAddress);
@@ -23,7 +23,7 @@ bool Platform::openWebBrowser(const char* webAddress)
 
    return false;
 }
-
+#endif
 #ifdef TORQUE_DEDICATED
 // XA: New class for the unix unicode font
 class PlatformFont;