(Re)added the getProperties() method as deprecated

Added a getProperties() method to the IConfiguration to support projects,
which depend on the old function. The method is deprecated and
simply uses the added methods exportDefaultConfiguration() and
exportConfiguration(). The method getProperties() might be removed in
the next version.

Change-Id: Iceefbb35b6a58859b8410ccc02f58b16488c558e
Signed-off-by: Peter Merkert <p.merkert@sap.com>