Revision history for SNA-Network
0.21  2016-01-29
      - betweenness algorithm now includes edge betweenness
      - normalisation is now optional in betweenness algorithm
      - communities method returns an empty list by default (fixed bug #100384)
0.20  2014-11-20
      - introduced a new community structure class
      - Louvain method now stores the hierarchical structure
0.19  2013-04-16
      - added module values and modularity methods for community classes
      - fixed Louvain algorithm's erroneous quadratic memory consumption
0.17  2012-10-29
      - maintenance
0.17  2012-09-27
      - fixed the MCMC Generator not to produce multi edges
0.16  2012-09-05
      - added Markov Chain Monte Carlo (MCMC) Generator
0.15  2012-08-17
      - core algorithm accelerated by an order of magnitude
      - added method total_weight() to SNA::Network
      - added Louvain community detection algorithm with some basic community handling code
0.14  2012-08-06
      - added direct generators I<new_from_$format> in Guess and Pajek Filters
      - added create_node method with automatic indexing
      - pagerank algorithms accelerated by factor 2 using forward propagation of values
0.13  2010-11-12
      - added algorithm for in-core collapse sequence
0.12  2010-10-08
      - added missing test network
      - linked all submodules in the main documentation
0.11  2010-09-15
      - added algorithm for betweenness centrality
0.10  2010-09-06
      - fixed bug in PageRank calculation without any sink nodes
      - fixed bug in PageRank calculation with a damping factor of 0
      - added special PageRank calculation for weighted networks
      - fixed bug in repeated identification of weak components after a change of network structure
0.09  2010-09-01
      - internal changes to improve speed, API unaffected
      - use of Object::Tiny::XS for accessors
0.08  2010-07-28
      - Fixed missing dependency Test::Mem::Cycle
      - Added PageRank Algorithm
0.07  2010-07-14
      - Fixed memory leak in edge deletion
0.06  2010-07-12
      - Fixed bug in edge deletion: edges stayed in node's edge reference list
0.05  2010-04-20
      - Internal speed-up using hash keys directly instead of sub calls
      - Changed node degree methods to ignore weights
      - Introduced specific node degree methods respecting weights
      - Fixed memory leak: networks with cycles were not freed after usage
0.04  2009-08-25
      - Fixed edge deletion in some special cases
      - Added missing test file to MANIFEST
0.03  2009-07-07
      - Introduced weak component identification
0.02  2009-03-12
      - Introduced support for network and node plugins
0.01  2009-03-09
      - First version, released on an unsuspecting world.