Work also with newer networkx (tested with 2.1).

Reportedly still works with old version.

Also, just return 0.0 for link utilization when we are missing
capacity information for the link and output a warning.

Fixes crash when undoing simulated router failures.

  * Add compatibility with NetworkX >= 1.6.
  * Use simple file reads in pajek.py
  * Add support for 100G interfaces

Remove extra whitespace-suffix for completions. Seems newer python readline versions no longer require this.

Conflicts:
	command.py
	utils.py