Converting build system to waf

NDNx and SSL locations can be controlled using --ndnx and --openssl
command-line arguments to ./waf configure

In addition to checking if SSL library works, check if selected/detected
SSL library matches with the one used during NDNx compilation

Change-Id: I79a9d7a43235b5d57234325fa8d12f6148c20de2
Conversion of test scripts to unittest + nose

Tests can be run by ./waf test can be run (after ./waf install)

Also, one can also run `nosetests' command directly, assuming pyccn is
installed in a standard location or PYTHONPATH environment variable is
correct set up

Change-Id: Ib5a7337baa9c8524268a4483d637df292396dbc9
New method KeyLocator.getDefaultKeyLocator () that relies on new API available in NDN fork of CCNx

Also, Key.getDefaultKey() method that is the same as Face.getDefaultKey()

Change-Id: I1b990343c8b96bd5c2dcdd9df8fbc9a0d43213ad
Updating documentation files to reflect latest changes (rebranding and updated API)

Change-Id: I838a13a8c456c6f7cb4cb1be8c2dcc649e129e60
Fix compilation warning from gcc 4.2.1 on FreeBSD

Change-Id: Idc952bd9f296231992ddd4dccb52304be1afd682