Refactor spec/trema_spec.rb
Refactor spec/trema/controller_spec.rb
Refactor spec/trema/error_spec.rb
Refactor spec/trema/port-status_spec.rb
Fix spec/trema/packet-out_spec.rb with Ruby 2.0
Use paper_house 0.4.0
update README
glib2.0 library used by packet-openflow.so
Fix some cucumber scenarios (Ruby 1.9/2.0).
Merge branch 'develop' of https://github.com/trema/trema into develop

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# especially if it merges an updated upstream into a topic branch.
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# the commit.
Version bump.
Merge branch 'release/0.4.0' into develop