Slow performance of Clique Census algorithm implementation

[oxy86]

SocNetV can find all maximal cliques in an (un)directed graph, using an implementation of the Bron–Kerbosch recursive backtracking algorithm that searches for all maximal cliques in a given graph G. Unfortunately, that implementation is not sophisticated (i.e. uses default QSets very oftern) and it is thus very slow on networks of high density and more than 2000 of edges.

• In future versions, we need to come up with a better implementation of this.
• Until then, a message to the user about the slow performance of Clique Census would be nice.