Stop filtering by input type

IE7 was throwing the error 'permission denied'. The problem seemed to be caused by the selector being used to find the form input; it failed when trying to match an input with a particular ID against the different input types. This worked fine, for example:

````javascript
$field = $(
  "input#" + for_attr + "[type='text']," +
  "textarea#" + for_attr
);
````

So I assume that IE7 is barfing on a selector that contains an ID and input type that do not match.

I could have edited the code so that it looked up the type first and then matched it against a list of allowable values, but I think it's better to just match against all input and textarea elements. Since we're working with IDs, we should trust the user to know the type of element they are working with.