* fixed cpdag() and cextend(), which returned an error about
the input graph being cyclic when it included the CPDAG of
a shielded collider (thanks Jean-Baptiste Denis).
* do not generate observations from redundant variables (those
not in the upper closure of event and evidence) in cpdag()
and cpquery().
* added Pena's relevant() nodes identification.
* make custom.fit() robust against floating point errors
(thanks Jean-Baptiste Denis).
* check v-structures do not introduce directed cycles in the
graph when applying them (thanks Jean-Baptiste Denis).
* fixed a buffer overflow in cextend() (thanks Jean-Baptiste
Denis).
* added a "strict" argument to cextend().
* removed Depends on the graph package, which is in Suggests
once more.
* prefer the parallel package to snow, if it is available.
* replace NaNs in bn.fit objects with uniform conditional
probabilities when calling as.grain(), with a warning
instead of an error.
* remove reserved characters from levels in write.{dsc,bif,net}().
* fix the Gaussian mutual information test (thanks Alex Lenkoski).
a9190bbc1d