Default group names cause duplicates

[paul-ruth]

By default Flukes names groups "NodeGroup0", "NodeGroup1", etc.

I you have an active slice that contains an active group called "NodeGroup0" and you add a new group, the new group will also be called "NodeGroup0". It works fine If you submit the modify request with the duplicate group names (likely it is enough that the guids are different). The problem is that the resulting manifest view in Flukes has duplicate node names and the user can not easily know which is which.

This is not that big of a deal because: 1) it works anyway, and 2) interesting slices probably have purposely named groups/nodes. This is probably why I just noticed this while working on modify for ndllib.