See #5426.

10% of times the data is not just "item 0" but there is also the
"otherfield" part. Use [lrange] to avoid the issue.
This commit fixes #4416.

After checking with the community via Twitter (here:
https://twitter.com/antirez/status/915130876861788161) the verdict was to
use ":". However I later realized, after users lamented the fact that
it's hard to copy IDs just with double click, that this was the reason
why I moved to "." in the first instance. Fortunately "-", that was the
other option with most votes, also gets selected with double click on
most terminal applications on Linux and MacOS.

So my reasoning was:

1) We can't retain "." because it's actually confusing to newcomers, it
looks like a floating number, people may be tricked into thinking they
can order IDs numerically as floats.

2) Moving to a double-click-to-select format is much better. People will
work with such IDs for long time when coding / debugging. Why making now
a choice that will impact this for the next years?

The only other viable option was "-", and that's what I did. Thanks.