Don't use "|", because Calendars on OSX does not allow it.

Some applications strictly adhere to RFC4648. Calendars on OSX is one of those applications. While browsers accept the `|` character, Calendars (and others, I'd imagine) don't like it.

This is a backwards compatible change to the encoder, so that all URLs generated going forward do not have the `|` character. URLs that are in the wild with the pipe character will still be decoded properly.