Update din-1505-2.csl

add last changes to variants of din1505 style and unify their bibliography
Update din-1505-2.csl
Update din-1505-2-numeric.csl
Update din-1505-2-alphanumeric.csl

fix also surplus disambiguate year
Merge pull request #613 from mmoole/patch-3

Update din-1505-2.csl