Anonymous upload Feature as requested in #740 (post rebase)

This is the Anonymous Upload feature requested in issue #740 and discussed in PR #3038. I've opened a new PR based on my forks master branch as DeepDiver1975 asked me for a rebase. A new PR also makes it easier to take care of possible issues without the confusions of 70+ comments.

In this latest version I mainly removed duplicated code and responded to some of the comments within the old PR. All issues should be resolved now. Please give this version a try.