utils: draft implementation for queue drop tracer
src: Creating file to track current version of ndnSIM (in addition to git tags)

+ AUTHORS file
examples: Adding new example to illustrate use of L2Tracer to trace aggregate packet drop rate on nodes
docs: Documenting new L2Tracer with a scenario and graph building example
Merge feature branch 'feature-l2-tracer'
src: Update AUTHORS file
model+cs: Now it is possible to get pointer to ContentStore from cs::Entry

In some cases it is desirable to know which ContentStore (=on which
Node) a particular cs::Entry belongs to.  Now it is possible to
accomplish this task using cs::Entry::GetContentStore method.
docs: Adding google mirrors and new section referring to the recommended way to run custom simulation using the provided template
patches: Deprecating patches.  ndnSIM requires custom fork of NS-3
all: Replacing deprecated NameComponents class with Name

NameComponents is kept for backwards compatibility as typedef to Name

refs #29
all: InterestHeader and ContentObjectHeader refactoring to Interest and ContentObject

refs #29
all: Adding typedefs near forward declarations of Interest/ContentObject/Name

refs #29
model: Extending FIB and PIT interface to include Find call to search for exact match of FIB and PIT entry
src: Update AUTHORS
model+docs: Small corrections of Doxygen documentation for ndn::Face
model: Small extension of Name class

Now name can be also constructed from a list of strings (previously, there
were a constructor version accepting list of references to strings).
utils: (Re-)enabling printing "dropped" Interests/Data seen by ndn::ForwardingStrategy
model: Changing ForwardingStrategy trace output logic

As of now, ForwardingStrategy will report that packet has been
forwarded (OutData/OutInterest trace) any time packet was send out to the face, regardless
the actual status of a particular send (i.e., will report as send even if queue has
been overflown for a particular face).

Additional trace (DropData/DropInterest) will report all instances of
unsuccessful transmission of Data or Interest, including cases of queue
overflowing on faces, Interest collapsing, Interest limits drops, and other
level-3 "drops".
In simple scenarios, DropData+DropInterest should equal to TxQueue drops.
utils: Extending l2-rate-tracer to include raw packet counts

This is similar to the existing ndn-l3-rate-tracer
model: Refactoring PIT and adding experimental support for a new policy to count container operations