careful when deleting and renaming files.

 *  Fix: Don't crash on Java 8u252 which introduces an API previously found only on Java 9 and
    above. See [Jetty's overview][jetty_8_252] of the API change and its consequences.

 *  New: `MultipartReader` is a streaming decoder for [MIME multipart (RFC 2045)][rfc_2045]
    messages. It complements `MultipartBody` which is our streaming encoder.

      @JvmStatic
      fun bouncycastle() = PlatformRule(BOUNCYCASTLE_PROPERTY)

      @JvmStatic
      fun isAlpnBootEnabled(): Boolean =
        try {
          Class.forName("org.eclipse.jetty.alpn.ALPN", true, null)
          true
        } catch (cnfe: ClassNotFoundException) {
          false
        }

      val isCorrettoSupported: Boolean =
        try {