Move restrict functions to separate static class

Encapsulate these functions into classes, so we can use an autoloader later.
Add SabreZarafa namespace to all classes; fix namespace issues

Place all classes provided by Sabre-Zarafa into the SabreZarafa namespace, and
fix the issues that arise from not working in the default toplevel namespace.
Rename Zarafa_Logger class to just 'Logger'

We have our own namespace now, so no need to disambiguate the class name.
Backends: remove Zarafa_ prefix from classname

We have our own SabreZarafa namespace now; no need to disambiguate.
Rename Zarafa_Bridge to Bridge

We're using the SabreZarafa namespace now.
Rename Zarafa_Webaccess_Settings class to WebaccessSettings
Rename Zarafa_Folder class to Folder
Rename Zarafa_Store class to Store
VCardParser/VCardProducer: rename to Parser/Producer

Use namespaces; these are inside SabreZarafa\VCard.
Also rename the interfaces accordingly.
Move files into a PSR-0 dir structure, load with Composer
Bridge: remove excess whitespace

Seemed an appropriate time after moving the file to a new location.
No functional changes.
README.md: update for 0.22, remove outdated sections
Ignore .gitignore for archive tarballs
Remove superfluous, unused template file
server.php is responsible for loading MAPI libs and config

Since server.php is always the entry point for our application, make it
responsible for loading the MAPI libs, the config file, the version defines,
and so on. Also define our custom MAPI properties here, so that they are
available to all classes further on in the request.

This obsoletes 'common.inc.php'.