Progress on base64 decoding

Some kind of bug with multiple attachments, 1st overrides the 2nd...
base64 decoding functional

some xml2collection refactor, fix issue with leaving orphan file if
xmlScheme (Content-Desc) is unknown.
Merge remote-tracking branch 'upstream/master'
Fixed tests to match URL changes
Merge pull request #21 from moroni-pickering/master

After many rabbit holes, base64 decoding works