using MH whole vector version, without tuning, but mixing too bad. not moving at all.
try separate update next version
1. major correction; correct LLBiMix function
2. change MCMC M-H/Gibbs to block sampling
1. add loglikeo before theta
2. change transition prob for omega candidate
3. so far so good for individual updating
4. TODO: tuning
add tuning for mixture componentwise
1. set K from prior
2. set tuneinit = 0.1
3. (important) update beta2spc from fixed value to check MCMC, and from priors
4. add plot of beta2sp and betay in plot function