Coding guidelines adjusted

[Rod Widdowson]

> There is one huge checkin coming - the one which will convert.
> 
> @Nonnull public final Optional<ResolvedType> resolve(@Nonnull final
> AttributeResolutionContext resolutionContext)
>             throws ResolutionException
> 
> in BaseResolverPlugin to be
> 
> @Nullable ResolvedType resolve(@Nonnull final AttributeResolutionContext
> resolutionContext) throws ResolutionException

As discussed on Friday.  I have now done this work.