* Moved show_{topology,switch_status} to examples/topology
* Minimized show_topology example
* Add sample .conf file
* Add external attribute to show_switch output.
Refactor and merge apps/topology to trema.
Rename libtopology -> topology.  C API part for #3.
Add event filter operation. (#2)
I compile step definition should build in trema C compatible options.
Auto start topology daemon. (#5)
Fix a issue where read_pid was failing when a trema name was specified with -n or --name option.
Suppress invalid option error message.
Fix build on 32bit environment.