Merge pull request #1138 from wdjunaidi/master

Add java hamming
Separate account page and profile page
Tweak account page
Get completed assignments directly from database.
Do not reject future exercises
Ditch the summary page
Tweak 404 page
Delete superfluous methods
fix Perl 5 Queen attack test in case of exceptions
rewrite Perl 5 queen-attack test cases to be saner
Dedupe worked in languages
Merge pull request #1139 from szabgab/perl5-queen-attack

Perl5 queen attack
Reopen completed submissions if resubmitted
Fix broken build
Fix go etl test cases to match README.