on Ubuntu 14.04.1 LTS if nsupdate runs without port number given it treated argument following server name as port number.
and throws error:
```
port 'update' is not numeric
syntax error
```
The gandi api has changed its url for a more stable
one. Although https://dns.beta.gandi.net will continue to
work for the foreseable future, this commits updates the
url to new official one.
dns_dyn.sh, remove empty line at end
dns_dyn.sh, remove trailing spaces at end of line
Replace 'head -n' with the '_head_n' function
Update main README.md DNS API list