fcf: Derive all essentially new implicit edits
Description
Implements the Field Code Forest algorithm of Garfinkel
et al (1986) to derive all essentially new implicit edits
from an editarray. At the moment this algorithm has very
little optimization and can be very slow.References
R.S. Garfinkel, A.S. Kunnathur and G.E. Liepins (1986).
Optimal imputation of erroneous data: categorical data,
general edits. Operations Research 34, 744-751.