try to fix that the automatic build fails: check out if the build fails because of the https on the embl ftp server.

Fix issue #9 and #7: cost and class.weights are not hard-coded anymore, but will be taken out of the param.set parameters. Also, the alpha parameter for enet models can be a single value. Lastly, the documentation was updated to include a section about hyperparameters.

Close issue #13: half the size of models when using cvglmnet classifiers by *not* storing the call within the models.

Fix issue #14: used which for unmapped features as well and then a set operation to make sure that f.idx will not become empty if there is no overlap.