Minor simplication of composite_score constructor
Add power diversity_parameters::dst2dp

When the diversity penalty is a probability (as the Tanimoto distance
sorta is) it makes sense to multiply it with the score (which should
rather be a probability too) rather than subtracting it. Then it also
makes more sense to have the diversity pressure be the pth-power of
the diveristy penalty.
Minor simplication of composite_score constructor
Fix bug and improve comments related to pthpower diversity_parameters::dst2pd
Merge remote-tracking branch 'origin/composite_score_extension' into origin-composite_score_extension
Add user option to multiply diversity penalty by raw score instead of subtracting
Increase version to 3.6.6 (new user option)
Merge pull request #201 from ngeiswei/composite_score_extension

Composite score extension
Fix precision_bscore::best_possible_bscore (offset by 0.5)
Remove extra space
Add . separator to distinguish expansion from breadth first index
Merge pull request #202 from ngeiswei/fix_demeID

Add . separator to distinguish expansion from breadth first index
Modify policy of option --max-candidates so that it actually works

Select the top max candidates ignoring redundant or invalid candidates
without race condition (indeterminism).

This was the previous behavior before I replaced it with something
that would not account for redundant or invalid candidates, except it
is deterministic.

So this potentially modifies the behavior of MOSES, you might want to
lower --max-candidates to get back to similar behavior in term of
number of candidates merged.
Set moses version to 3.6.7 because the behavior has slightly changed
Merge pull request #203 from ngeiswei/max_pot_cnd

Max pot cnd
Add initial test unit for scoring.{h,cc}
Complete scoring unit test
Merge pull request #204 from ngeiswei/fix_precision_bscore_best_score

Add precision bscore best score unit test
Add assert to check for negative distance + log in diversity
Fix bug in max candidate merging