Mood swing

Fixes #90.
Is dependent on pull request #749 (option).
Requires database update 00090_mood_swing_01.sql

This implementation of mood swing is such that mood is a skill that can only be used with swing and twin swing dice. For all other dice, the skill is simply not added to the die. For twin swing dice, both component sub dice change their sizes to the same value.

http://jenkins.buttonweavers.com:8080/job/buttonmen-blackshadowshade/153/