First revision of the admin manual
Merge pull request #2 from filippocarletti/master

First revision of the admin manual
Cutted some extra text
Merge pull request #3 from alefattorini/patch-1

Cutted some extra text
Fix rst admonition syntax
Update mail.rst
Merge pull request #4 from filippocarletti/master

Fix rst admonition syntax
Update administration.rst
Cleaned update.rst
Merge pull request #5 from alefattorini/patch-2

Cleaned update.rst
Updated firewall.rst
Merge pull request #6 from alefattorini/patch-3

Updated firewall.rst
Merge branch 'master' of github.com:nethesis/nethserver-docs