Officially deprecate this and point to swiftclient

As of August 1, 2013, this package is deprecated. This change adds a
DeprecationWarning upon importing "cloudfiles", and it adds the same
warning upon installing. However, as DeprecationWarnings are silenced by
default as of Python 2.7, we programmatically enable them on install in
order to put the message out there.
Address Alex's comments - more descriptivewarning message
Merge pull request #92 from briancurtin/master

Officially deprecate this and point to swiftclient