Profile id and subscription search tests

I noticed a long time ago that TransactionSearch doesn't allow searching on ProfileID, yet the PayPal SOAP API does indeed support that.

In this pull request, you'll find the simple addition of allowing such a search.  Also included, though, is a new test based on my own code that uses this ProfileID search.

You'll see here too that I've made a new way of doing these test that require user action in the sandbox: by creating a little HTML file on the filesystem with a form that will create the order.  I hope you find this reasonable.  Ideally, this would be fully mechanized with WWW:Mechanize or somesuch, but this is a useful first hack, I think.

Any feedback or changes you need to accept this upstream would be welcome!

Finally, I hereby license my copyrights herein under the same license as Perl itself. :)