title: Sorting numeric-strings in Rails
body: <p>First, a caveat: I'm pretty new to Ruby and Rails.</p>
  
  <p>I've got a string field in my model which references an existing, offline naming scheme for my client, which are integers separated by decimals.  So "1.1" and "5.10.1.5", etc.</p>
  
  <p>I'd like to use Rails' default scope sorting but just a normal sort by this field causes issues like this:</p>
  
  <p>1
  1.10
  1.2
  1.3</p>
  
  <p>Clearly, I'd like 1.10 to be sorted at the end.  Can anyone point me in the right direction?</p>
  
  <p>I'm using Rails 3.2.10 and Postgres 9.1.4.</p>