tree 06e2cbc8e1a6d16437f9abea21d89de712aa6d49
parent abc19b0dd0aa852e52565288f44fbcb955c82183
author Shawn Pearce <sop@google.com> 1426130796 -0700
committer Shawn Pearce <sop@google.com> 1426202292 -0700

Move user stream IO setup to common PrologControl

This allows Gerrit Code Review's PrologShell to setup the
user_{input,output,error} streams the same way the other
repl code does

Streams are optional and are simply not registered if
passed as null.

Change-Id: I78ab48d8779a12d05b9109cada6048f4e08037f8