BeagleBone Black: Enabling UART

There are 4.5 UART ports that can be enabled on the BeagleBone Black.  The 0.5 occurs because there is only the transmit line (Tx) on UART3.  The process of enabling the Device Tree Overlay has been described before here:
http://beaglebone.cameon.net/home/serial-ports-uart

UART1:  [P9] Pin 24 - Tx, Pin 26 - Rx
UART2:  [P9] Pin 21 - Tx, Pin 22 - Rx
UART3:  [P9] Pin 42 - Tx (There is no Rx line)
UART4:  [P9] Pin 13 - Tx, Pin 11 - Rx
UART5:  [P8] Pin 37 - Tx, Pin 38 - Rx