Add username filter

[rurseekatze]

It would be very useful if there would be a possibility to hide the edits of one or more users by setting a filter with usernames.

When I am looking at my "home region", it would be very useful if I could hide my edits, so that I only see the acitivities of other mappers.

For checking vandalism or mistakes made by newbies, it would be useful if edits of even more users could be set as hidden. Then I could ignore the edits of myself and users which I trust, so that I only see suspicious changes.