[parrot/parrot] da3022: [cage] more const io api arguments

[GitHub]

  Branch: refs/heads/smoke-me/stringbuilder-gh1123
  Home:   https://github.com/parrot/parrot
  Commit: da30227be67784e8b1afda00d52daeca7ca5dd9b
      https://github.com/parrot/parrot/commit/da30227be67784e8b1afda00d52daeca7ca5dd9b
  Author: Reini Urban <rurban at cpanel.net>
  Date:   2015-01-31 (Sat, 31 Jan 2015)

  Changed paths:
    M include/parrot/io.h
    M src/io/io_private.h
    M src/io/pipe.c
    M src/io/stringhandle.c
    M src/io/utilities.c

  Log Message:
  -----------
  [cage] more const io api arguments