Add ExtremeXOS
Add Brocade NOS
Match IP address explicitly

- New method node_want?
- Don't match node to node[:name] if node[:name] is an ip address.
  Otherwise we might match to wrong ip address.
Return true if node_want is nil

- Otherwise all nodes can not be loaded.
Remove ntp clock-period completely

emj complained that it sometimes pops in, sometimes pops out. I guess
really no point having it there.
Fixed small bug in powerconnect enable code
Added model for cisco NXOS
Merge pull request #47 from emjemj/master

Small fix in powerconnect code and new nxos model
Removed ever-changing output from powerconnect model, thanks @artmann
Merge pull request #48 from emjemj/master

Removed ever-changing output from powerconnect model, thanks @artmann
Fixed more ever changing output in powerconnect model, only shows up on some firmware versions
Merge pull request #49 from emjemj/master

Fixed some changing output found in specific firmware versions
Added Cisco NXOS to the list of supported platforms
Merge pull request #50 from emjemj/master

Added Cisco NXOS to the list of supported platforms
Overhauling project README.md

Cleaning up documentation and adding new Cookbook examples.
Update README.md
Update README.md
Update README.md
Update README.md
Update README.md