convert Rails 2 finders to Rails 3 and 4 finders

These will work on Rails 4, so it should make the switch to Rails 4
easier.  The general strategy is to change :conditions to `where`,
:order to `order` etc.  Then we need to maintain method return value
compatibility.  IOW, methods that returned arrays should continue to
return arrays
Convert finders with condition hashes to Arel notation.