don't $I files when in skipped $IFDEF/$IF (RomanYankovsky#208)

If $INCLUDE/$I is found while in the $IF(N)DEF/$IF part which is being skipped (undefined conditional etc), include is ignored.

This speeds up parsing (especially if include file has to be found in a long search path) and makes the parser more compatible with Delphi which ignores $INCLUDE statements inside skipped blocks.

Source/SimpleParser/SimpleParser.Lexer.pas

@@ -1595,7 +1595,7 @@ procedure TmwBasePasLex.BraceOpenProc;
       begin
 //        if Assigned(FOnIncludeDirect) then
 //          FOnIncludeDirect(Self);
-        if Assigned(FIncludeHandler) then
+        if Assigned(FIncludeHandler) and (FDefineStack = 0) then
           IncludeFile
         else
           Next;