Using spatsoc in SNA vignette

spatsoc needs a vignette describing how to use it in social network analysis within the established R package environment (igraph, asnipe).

TODO:

• gambit of the group with group_pts
• gambit of the group with group_lines
• gambit of the group with group_polys
• data stream randomizations
• group by individual matrix
• integration with asnipe
• integration with igraph
• observed networks
• random networks