Examples of input streams
user input (already exists in the output window)
file input stream (just make one file as default input stream)
any external process
Examples of output streams
to output window (exist)
to a file (and possibly to output window)
Hasn't been addressed yet [NB 3.2 #39]
Target milestone -> 3.3.1.
Target milestone -> 3.4
Target milestone was changed from '3.4' to TBD.