Console API made closest to original one

Extended I/O procedures (CoreLite-like) removed, initial Read/ReadLn procedures added to System unit.

Examples/Console/LoadFile/LoadFile.dpr

@@ -10,5 +10,5 @@ var
 begin
   InitConsole('Load File');
   Buffer := LoadFile('/sys/example.asm', FileSize);
-  WriteLnEx(Buffer, FileSize);
+  con_write_string(Buffer, FileSize);
 end.