If the number of columns is zero, do not wrap.

Sometimes HighLine might return non-nil yet zero value. You can reproduce by

<pre>
# stty columns 0
# rhc cartridges
</pre>

Addressing
<pre>
/usr/lib/ruby/gems/1.8/gems/rhc-1.10.1/lib/rhc/core_ext.rb:100:in `textwrap_ansi': can't do {n,m} with n > m: / (RegexpError)
      (
        # Match substrings that end in whitespace shorter than limit
        (?:(?:\e\[\d+(?:;\d+)*[@-~])+.?|.(?:\e\[\d+(?:;\d+)*[@-~])*){1,0}
        (?:\s|$)                     # require the limit to end on whitespace
        |
        # Match all continguous whitespace strings
        (?:(?:\e\[\d+(?:;\d+)*[@-~])+.?|.(?:\e\[\d+(?:;\d+)*[@-~])*)+?
        (?:\s|$)
        (?:\s+|$)?
      )
      /
	from /usr/lib/ruby/gems/1.8/gems/rhc-1.10.1/lib/rhc/highline_extensions.rb:40:in `say'
	from /usr/lib/ruby/gems/1.8/gems/rhc-1.10.1/lib/rhc/commands/cartridge.rb:63:in `list'
	from /usr/lib/ruby/gems/1.8/gems/rhc-1.10.1/lib/rhc/highline_extensions.rb:177:in `call'
	from /usr/lib/ruby/gems/1.8/gems/rhc-1.10.1/lib/rhc/highline_extensions.rb:177:in `section'
	from /usr/lib/ruby/gems/1.8/gems/rhc-1.10.1/lib/rhc/highline_extensions.rb:191:in `paragraph'
</pre>