PyNDN: More fixes

Refs #1010 (http://redmine.named-data.net/issues/1010)
Merge branch 'release-0.5'
model: Fixing warning in ndn-wire.cc
build: Fixing build problem with python bindings enabled, but visualizer disabled
plugins/ip-faces: ip-faces plugin, which implements ndn::TcpFace

This commit also includes a basic example showing how to work with
TcpFace.  The code compiles and passes basic tests, but requires more
work and proper documentation

Refs #1006 (http://redmine.named-data.net/)
build: Adding tricks to suppress unwanted warnings from clang (originated from boost)
plugins/ip-faces: Initial implementation of UdpFace

Refs #1006 (http://redmine.named-data.net/)
plugins/ip-faces: Updating TcpFace implementation

In addition to changes to follow latest API changes in ndnSIM, the
helper ndn::IpFacesHelper allows scheduling TcpFace creation at specific
point of simulation.

Refs #1006 (http://redmine.named-data.net/)
plugins/ip-faces: Implementing UdpFace and fixing bugs with TcpFace

Now UdpFace is fully working. Due to nature of UDP transmission, all
demultiplexing is happening inside IpFaceStack (with TCP, NS-3 is taking
care of that).

Bugfix: Map between IP addresses and Tcp/Udp faces was incorrectly
embedded as a static variable inside Udp/TcpFace implementation, causing
unexpected behavior.

Refs #1006 (http://redmine.named-data.net/)
Merge branch 'feature/tcp-and-udp-faces'