new termination rule for scg
Merge branch 'devel' into mrd
added logexp_clipped transformation
SCG convergence tolerance increased, will now converge more easily
conjugate gradient optimizer without callback (no c.join)
BGPLVM MRD Examples and plotting adjustments
Scale Factor removed and moved V=Y*beta into likelihoods
last changes for mrd stability
Merge MRD stability and scg termination rule into devel