role,race,&c options: environment vs config file

Due to the unorthodox values for role, race, gender, and alignment,
specifying a negated value or set of values in NETHACKOPTIONS wasn't
overriding a specific value set in the run-time config file.  The
command line should take priority, then environment, then config file,
lastly builtin defaults.

This could probably use some improvement.  It now treats role:!val
as if there was no val role and the entry was role:random rather than
previous role:none (affects prompting).

[I've just realized that role:!foo in environment will be combined
with role:!bar in config file rather than replacing it.  I'm not sure
how to deal with that.]

doc/fixes3-7-0.txt

@@ -1070,6 +1070,8 @@ throwing recoil while levitating could send hero out of shop while carrying
 	a step other than back into the shop was treated as a robbery
 if punished and iron ball was cursed and wielded--so welded to hand--falling
 	when doors would drop it instead of keeping it welded
+if player's run-time config file had OPTIONS=role:Val and the environment had
+	NETHACKOPTIONS='role:!Val' the hero would be a Val instead of !Val
 
 
 Fixes to 3.7.0-x Problems that Were Exposed Via git Repository