Added a CLI Manager using the Urwid library
Added docstrings in the CLI Manager functions
The Urwid library is now added to the sys.path in the main centralreport.py module
Added a "DialogBox" object in the CLI module

Used to interact with the user, displaying texts or errors.
Linked "Config" class to the CLI Manager
Improved Dialog object in the "cli" module
Improved CLI Manager with major improvements

- The manager must be run as root to perform some tasks (write new configuration, restart the daemon, …)
- CentralReport must be already installed on the current host to run the CLI Manager
- The configuration for the internal web server is now written in the configuration file
- The daemon restart when the user exit the CLI Manager to use the new configuration

PS: We must work on the "feature-webservices" branch to finish this PR for the "Online configuration" part.
[WIP] Working on CLI Manager (MainCli, palette colors, Update the configuration, …)
Improved CLI screens
Major improvements in the CLI Manager

- The port for the internal web server is now checked when the user choose one new
- The main screen is now refreshed when the user modifies the configuration
- The daemon status ("CentralReport is not running" / "CentralReport is running with PID xxx") is now updated when the user starts/stops/restarts the daemon
- The daemon status is modified when the daemon is starting/stopping ("Starting CentralReport…" / "Stopping CentralReport…" / "Restarting CentralReport…")

Tech:
- The urwid main_loop is now located in the "WindowCli" class. It's more logical and can be updated directly within the object.
Added "manage" option to the binary script for the CLI Manager

Now, we can start the CLI Manager with the command "centralreport manage" (or "/usr/local/bin/centralreport manage").
The CLI wizard is now started at the end of the installation
Removed all references to CentralReport Online

This part will be added in a future release.
In the binary file, the "manager" parameter is now used to start… the CLI Manager.

(Was "manage" before)
Updated NEWS file for #82 (CLI Manager)
Merge remote-tracking branch 'origin/develop' into feature-manager

Conflicts:
	NEWS
Minor spelling fixes
Merge pull request #82 from CentralReport/feature-manager

CLI Manager