Page up & Page down produce multiple keypresses in readkey #14

Not sure how general this issue is, but page up & page down in my terminal (OSX built-in "Terminal" application) produce the sequences ^[[5~ and ^[[6~ respectively. However, readchar.readkey produces two character sequences for these keypresses: ^[[5, ~ and ^[[6, ~. I expect them to produce just one sequence each.

What's surprising is DELETE has a similar escape code ^[[3~ which works properly.