Add features test for topology C API
Refactor and merge apps/topology to trema.
Rename libtopology -> topology.  C API part for #3.
Move .features to match new features/ directory structure.
Add event filter operation. (#2)
I compile step definition should build in trema C compatible options.
Auto start topology daemon. (#5)

* Kill topology before/after libtopology unittests
Fix a issue where read_pid was failing when a trema name was specified with -n or --name option.
Suppress invalid option error message.
Merge branch 'fix_read_pid_check' into topo-trema-C
Add features test for topology Ruby API
Add Topology Ruby API
Fix for libtopology.h -> topology.h. Closes #3.
Add Ruby version of show_topology example. (#4)
Add Ruby version of show_switch_status. (#4)
Add Topology caching Ruby API example change-history.rb (#4)
Use expect instead of should
Move .features to match new features/ directory structure.
Refactor Ruby API (#8)
* Remove _ready events.
* Subscribe only if necessary at #start
* Add block callback form to subscribe/unsubscribe
* Do not inherit Hash.
* Rename Cache to Map.
* Prefix send_ for method which sends request to topology daemon.
* send_ methods now return send result.
* Add/Update YARD document.
* Remove raw property status/external
* Some other refactoring before removing non-primitive API.
Removed Map API (#8)