close #411 segments should not be allowed where node_a == node_b
-rw-r--r-- 888 README
-rw-r--r-- 307 Rakefile
drwxr-xr-x - app
drwxr-xr-x - config
drwxr-xr-x - db
drwxr-xr-x - doc
drwxr-xr-x - lib
drwxr-xr-x - public
drwxr-xr-x - script