* Removed all Qt3Support dependencies from the 'RDUpload' class.
* Removed all Qt3Support dependencies from the 'RDDownload' class.
* Added a 'test_download' test harness.
* Cleaned up memory leaks in 'RDAudioExport', 'RDAudioImport',
'RDAudioStore', 'RDCart', 'RDCopyAudio', 'RDPeakExport',
'RDRehash', and 'RDTrimAudio'.
* Modified Xload operations in 'RDDelete', 'RDDownload' and
'RDUpload' to work properly with credentials using UTF-8 strings.