AbstractSmrPlayer: use self whenever possible
AbstractSmrPlayer: use self whenever possible

Replace explicit occurrences of (Abstract)SmrPlayer with `self`, which
is more robust because it doesn't depend on the name of the class.

hemberger/smr,hemberger/smr,smrealms/smr,smrealms/smr,smrealms/smr,hemberger/smr,hemberger/smr