[igraph] Induced subgraph isomorphism

[Raphael Clifford]

I realise this is asking a lot but, I was wondering if anyone had (or
had any plans to have) implemented a heuristic for induced subgraph
isomorphism.  If I am correct, the current VF2 implementation would
say that a-b-c-d is isomorphic to a subgraph of a 4-clique while it is
not an induced subgraph. (See
http://en.wikipedia.org/wiki/Induced_subgraph_isomorphism_problem.)

Raphael