don't throw error drawing empty container
plothist2d
Merge remote-tracking branch 'upstream/master'
Mention that 'nothing' is allowed when defining axis range

I was going to file a feature request for this very nice detail, but it seems it already works! ;-) So better document it. I hope I got it right.
Merge pull request #101 from natj/plothist2d

plothist2d
Merge pull request #103 from nalimilan/patch-1

Mention that 'nothing' is allowed when defining axis range
replace Winston.display -> display where appropriate
merge upstream