Remove swank dependency; that should be in the user's lein profile.clj, not in a library project.clj.
As of LIBLINEAR 1.91 Problem target classes are doubles, not integers. Closes #2.

See: https://github.com/bwaldvogel/liblinear-java/commit/283f7f3d4e465cc07138aca536732520e2fe9ddf#L8L39
Fixup whitespace.
Use clojure.edn/read-string instead of clojure.core/read-string for security.
Add type hints.
Update merge and adjust crossfold to only allocate target if requested.