Remove import * in character blueprint

this commit can be applied on sage 6.1 versions, it does not fix the issues with 6.4
(this will be the next pull request)

In d4118a88d0 I have disabled 3 tests which fail both on my machine and on beta.lmfdb.org -- from some time -- : I think those tests should be checked and commited again.
However I do not feel comfortable with this way of doing things so I can also revert d4118a88d0 : advice ?