Allow returning objects responding to :to_s from an Arbre block.

[utkarshkukreti]

Not sure if this is the best way to do this.

I wasted a few minutes trying to figure out why this wasn't working, until I found that only Strings were being accepted by the block.

column "Post Length" do |post|
  post.content.size
end

[ebeigarts]

+1. I think the method name should also be changed from insert_text_node_if_string to insert_text_node, since it now accepts any Object with to_s method.

[mattvague]

+1

[gregbell]

Fixed on master in 9cb2b90