Add ability to log to stderr

[haywood]

This is actually something that's generally very annoying about the echo command, and it would be nice to have some kind of switch that just turns it on.

[haywood]

maybe something like
log 'msg'
info 'howdy!'
error 'oh no!'

[nathanstilwell]

I love this idea. Anything to make errors prettier and easier to read. 👍

[p1r473]

@nathanstilwell what about ability to log to syslog?