fix a typo
update Controller::send_packet_out() YARD text
Merge pull request #327 from infrastation/develop

minor documentation fixes
Add Trema::Port#dpid.
Merge pull request #329 from trema/feature/port_dpid

Add Trema::Port#dpid.
Version bump.
Merge branch 'release/0.4.5' into develop
Enabled guard-bundler.
Finalize OpenFlow application interface properly.
Merge pull request #330 from shun159/feature/pio_arp_simple_router

Updated simple-router
Merge pull request #328 from trema/feature/pio_arp_simple_router

Replace ARPRequest/Reply with Pio::Arp::Request/Reply
Merge pull request #331 from shun159/feature/pio_arp_simple_router

Deleted IPAddr Class
Move all methods in RouterUtils to SimpleRouter.
Deleted undefined constant