Standardized ability score abbreviation display

When the ability score abbreviation is used on its own or as a +Score there was variation in displaying it. In most cases, the score was in sentence case (e.g. Str) more often than it was in all caps (e.g. STR). I made the less-frequent all caps version into sentence case. This might lead to a larger discussion to determine if sentence case or all caps should be used or if different displays should be used under different circumstances.

I added my name to the contributors as requested in read me, though the above-mentioned effort may not warrant such status.