Make cucumber buildable with jruby

I've made some changed to make cucumber buildable with JRuby (only latest version)
and added jruby to list of Travis configurations.
For now I've just mark most jruby specific failures as either pending (for specs) or @wip-jruby (for features).
I want have future changes tested with jruby and hope someone will eventually fix all pending tests.
Created separate PR for this to run it on Travis and discuss.