apps: Fixing bug with setting Size/MaxSeq in ndn::ConsumerWindow

Before this fix, recently introduced alternative MaxSeq, made parameter
Size essentially useless.
utils+apps: Fix a bug in ndn::RttEstimator

In the constructor of ndn::RttEstimator, the code tries to set
m_currentEstimatedRtt to m_initialEstimatedRtt using the ConstructSelf()
technique. However, it doesn't take effect at this point since
ndn::RttEstimator hasn't defined GetInstanceTypeId().

According to the manual
(http://www.nsnam.org/docs/manual/html/attributes.html#initialization-order),
"the object and all its derived classes must also implement a virtual
TypeId GetInstanceTypeId (void) const; method. Otherwise the
ObjectBase::ConstructSelf () will not be able to read the attributes".
GetInstanceTypeId() was defined in the original RttEstimator but was
somehow lost during the port to ndnSIM.

closes #40
model: Removing assert when interest payload is not zero

In CSMA channels, the minimum required length of a transmitted packet is
46 bytes, resulting in automatically added "payload" to some short
interest packets.  There is no problem of ignoring the assert, as it was
intended only for debug purposes, to ensure that decoding was done
properly.
model: Fixing segfault resulting from removal of FIB entries via Fib::RemoveFromAll call

The underlying policy was not notified about the removal, resulting in
further accesses to unallocated memory (e.g., during final clean up)
model: New trivial implementation of ContentStore (ns3::ndn::cs::Nocache)

This implementation completely disables all caching (this trivial implementation
is more efficient than content store with custom no-caching policy)
doc: Small update with packet format description
helper: Extending customization of Face creating in ndn::StackHelper
examples: New example showing how to activate link weights for global routing controller calculations
model: fix of a small syntactic error with templates (not all compilers complain)
utils: LocalInfoTag to track face information
Slight update of packet format: adding overall packet length to the
common header
utils: Adding ability to install ndn::L3AggregateTracer on individual nodes
model: *BUG* Fixing error regarding Freshness

Freshness policy was not behaving as expected.  Instead of keeping items
in the freshness container ordered by time, accidental use of
"push_back" method instead of "insert" completely invalidated the ordering.

Closes #41 (http://github.com/NDN-Routing/ndnSIM/issues/41)
Refs #1003 (http://redmine.named-data.net/issues/1003)
docs: Extending list of research papers
docs: Update list of research papers that use ndnSIM
topology-reader: Adding ability to specify custom queue type in topology files (AnnotatedTopologyReader)

Implements feature #1004 (http://redmine.named-data.net/)
src: Adding LICENSE file and updating license statements in several files
tracers: Extending helper API in tracers

Now all tracers can be installed on individual nodes.

It is also possible to specify "-" as a file name, leading to tracing on
standard output.

Refs #1007 (http://redmine.named-data.net)
tracers: New metrics in L3RateTracer

L3RateTracer now has 4 new per-face metrics:
- InSatisfiedInterests: a number of satisfied interests where face was
  part of the incoming set
- InTimedOutInterests: a number of timed out interests where face was
  part of the incoming set
- OutSatisfiedInterests: a number of satisfied interests where face was
  part of the outgoing set
- OutTimedOutInterests: a number of timed out interests where face was
  part of the outgoing set

Basically, for each face, sum of InSatisfied and InTimedOut (or sum of
OutSatisfied and OutTimedOut) equals to the number of totally received
(or forwarded) interests on the face.

Refs #1007 (http://redmine.named-data.net)
ndn.cxx: Initial work to introduce full NDN application API to ndnSIM

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