Retry setting unknown cvars after CVARINFOs are processed.

- Fixed: Using +set cvarname and +cvarname on the command line would not
  work if cvarname was defined in CVARINFO. This should be the proper way to fix
  it. Rather than move all command line execution after loading CVARINFO,
  keep command line execution before wads are loaded. If an attempt is
  made to set an unknown cvar or to run an unknown command (which could
  potentially be shorthand for setting an unknown cvar), save it and try
  running it again after all CVARINFOs have been handled.

src/d_main.cpp

@@ -2290,6 +2290,9 @@ void D_DoomMain (void)
 		// Now that wads are loaded, define mod-specific cvars.
 		ParseCVarInfo();
 
+		// Try setting previously unknown cvars again, as a CVARINFO may have made them known.
+		C_ExecStoredSets();
+
 		// [RH] Initialize localizable strings.
 		GStrings.LoadStrings (false);