propagate CT_KERNEL through config
propagate CT_KERNEL
add get_proposal_log_ratio helper

use in transition_feature_mh and pass to mh_choose
BUGFIX: do proposal ratio "better" (still looks bad in geweke)
BUGFIX: properly calculate proposal logps

wasnt taking log of #views
also, add helper get_proposal_logp to simplify logic
BUGFIX: pass correct value to draw_rand_i
BUGFIX: FIX MH!

issue was a sign flip on remove_feature output
limit #chains to 4
Merge branch 'test_CT_KERNEL'