Strong Valkyries "clumsily throw" Mjollnir

[Ardub23]

War hammers are treated as non-thrown weapons, meaning you only "clumsily" throw them and abuse wisdom. In the code within throw_obj() that determines whether a weapon is built for throwing, there's an exception for aklyses due to their autoreturning property, but no such exception is made for Mjollnir.

While it may make some thematic sense for non-Valkyries to throw it clumsily even when meeting its 25 strength requirements, I don't think it's fitting for Valkyries who can harness its returning property. Plus it's inconvenient to click through the paranoid throw confirmation when it's time to shoot lightning at bad guys.

I noticed there's an AutoReturn() macro in the code—maybe the aklys check could be replaced with that?