improve shading of alg DMD and tweak cpu timing based on pdf from oreganosystems.at

git-svn-id: svn://svn.code.sf.net/p/pinmame/code/trunk@3603 6f51dfdd-75df-4273-8f3b-818b1e6aa8bf
hack to double the 8031 clockrate for mystery castle

..'fixes' DMD animations, but doesn't make any sense

git-svn-id: svn://svn.code.sf.net/p/pinmame/code/trunk@3604 6f51dfdd-75df-4273-8f3b-818b1e6aa8bf