Allow bluetooth:// URLs to be parsed by java.net.URL.
Sets a stream handler in FDroidApp which understands bluetooth://
URLs and returns a non-functioning URL handler for such URLs.
The reason it is non-funcitoning is because the openConnection()
function is not being used by the BluetoothDownloader at this point.
In the absense of this, a MalformedURLException is thrown.
The bluetooth stuff is still broken, but it is not broken in
this way any more.