model: Returning back support for CCNb wire format

Refs #1005 (http://redmine.named-data.net/)
model-wire-ccnb: Fixing a known bug with CCNb parsing

Refs #1005 (http://redmine.named-data.net/)
model: Adding ability to select desired default wire format

ndnSIM will accept and process (if no modifications required) packets in
any supported wire format (right now it is only ndnSIM and ccnb).
Wire format for creating of new packets can be selected (per-face)
thorough ns3::ndn::Face::WireFormat variable.

Refs #1005 (http://redmine.named-data.net/)
apps: Adding ability to ndn::Producer to configure desired fake signature and key locator (key name)

Refs #1005 (http://redmine.named-data.net/)
examples: ndn-simple-with-pcap example now used CCNb packet format

The output of the example can be parsed using, for example, ndndump tool
(https://github.com/named-data/ndndump):

   ndndump -o -o ndn-simple-trace.pcap

Refs #1005 (http://redmine.named-data.net/)
python: Rescanned bindings

Refs #1005 (http://redmine.named-data.net/)