Fix drush component option description and allow for using form keys in component option

Confirmed, but it's not clear what we want. I think the intention of prefixing the submission info fields with webform_ is to prevent conflicts with actual component form keys. But the command doesn't accept form keys, but rather component cid's.

I see three options for this isssue:

1. Your #1 patch.
2. Leave description, but strip by add webform_ prefix for the user for non-numeric values.
3. Leave webform_ prefix as required, but also accept form keys in addition to cids, and adjust description to suit. A integer entry is a cid, an entry that starts with webform_ is a submission info, and anything else is a form key.

I like Option 3 myself. Comments?

Very nice. My comments are trivial and stylistic only. I haven't tested it yet, but it looks good.

1. +++ b/webform.drush.inc
   @@ -65,6 +65,20 @@ function drush_webform_export($nid = FALSE) {
   +
   ...
   +
   

   Unneeded blank lines.

2. +++ b/webform.drush.inc
   @@ -65,6 +65,20 @@ function drush_webform_export($nid = FALSE) {
   +    $form_key = $component['form_key'];
   +    $form_keys[$form_key] = $cid;
   

   Combine these lines, I think.

3. +++ b/webform.drush.inc
   @@ -65,6 +65,20 @@ function drush_webform_export($nid = FALSE) {
   +
   

   Need an unset of $component. Reference loop variables are PHP timebombs.

Thanks very much!

To clarify my third comment, I don't object to reference loop variables, but they need to be unset immediately after to loop. If you happen to (maybe years later) reuse that variable name, it will still be a reference, leading to much hair pulling. I restored your original version of the loop and added an unset.

Committed to 7.x-4.x and 8.x.

Also, one tiny request: if you name patches according to the Drupal convention, it is easier for maintainers to track them.