Merge branch 'release0.3.17' into develop
Workaround for Relish
* Groups should not be nested
* Group name(=directory name) should not contain '-'
* Highlight Ruby code
Merge pull request #291 from y-higuchi/switchd_branching

Workaround for Relish
Fix the permission of openflow-1.0.0/include/openflow/* (fixes #293).
Version bump to 0.3.18
Merge branch 'release0.3.18'