Merge branch 'new_model_impl' of git+ssh://scm.mulcyber.toulouse.inra.fr//var/lib/gforge/chroot/scmrepos/git/spel/spel into new_model_impl

Replaced cumbersome XML marker obs spec implementation with a sexier json-based one. More user-friendly too.

Merge branch 'new_model_impl' of git+ssh://scm.mulcyber.toulouse.inra.fr//var/lib/gforge/chroot/scmrepos/git/spel/spel into new_model_impl

Bayesian computation seems to work but we still need the output in the
form of locus vectors.

This one is good, the old code was so bad and ugly.

Implemented on-line computation of the product of N factors and projection on a subset of variables.

New implementation working fine. Factor graph properly built with joint factors as appropriate and spanning tree computation.

WIP.

Commit la grenouille.