migrate open SourceForge bugs and features to GitHub

[cjfp]

There are two open feature requests and four open bug reports at SourceForge. These should be migrated to GitHub. This can be done manually for such a small number, but there are also automated solutions like:

https://stackoverflow.com/questions/4627241/migrate-sourceforge-tickets-to-github-issues

An automatic solution might be good for migrating closed bugs, features, and patches too. If the tickets have already been migrated they should be closed on SourceForge and marked as migrated.

https://sourceforge.net/p/check/bugs/

https://sourceforge.net/p/check/feature-requests/

This might be a good issue for a new maintainer to resolve.