Import readline module for better text entry

[jbteves]

In vtcmd, arrow keys do not work correctly. In Python3, you can resolve this by importing readline, which will allow standard shell behaviors before the input is loaded into the program. e.g.,

thing = input('>>>')

Followed by ACB<-<-, will result in ACB[[A[[A| (with | the cursor location) on some systems.
However,

import readline
thing = input('>>>')

Followed by the same will result in the desired A|CB.