Relax the scope requirement on pseudo-scoped beans

Currently, the specification says that non-`@Dependent` beans may not have
public fields. This is overly restrictive; in particular, implementing this
rule precisely precludes passing the AtInject TCK, where `@Singleton` beans
have public fields.

This commit relaxes the requirement: all pseudo-scoped beans may have public
fields; normal scoped beans may not. This makes most sense, it is what all
existing implementations do (checked ArC, Weld and OpenWebBeans) and it is
how the TCK is already written.

spec/src/main/asciidoc/core/implementation.asciidoc

@@ -20,8 +20,8 @@ A _managed bean_ is a bean that is implemented by a Java class.
 This class is called the _bean class_ of the managed bean.
 The basic lifecycle and semantics of managed beans are defined by the Managed Beans specification.
 
-
-If a managed bean has a non-static public field, it must have scope `@Dependent`. If a managed bean with a non-static public field declares any scope other than `@Dependent`, the container automatically detects the problem and treats it as a definition error.
+If a managed bean has a non-static public field, its scope must be a pseudo-scope.
+If a managed bean with a non-static public field declares a normal scope, the container automatically detects the problem and treats it as a definition error.
 
 If the managed bean class is a generic type, it must have scope `@Dependent`. If a managed bean with a parameterized bean class declares any scope other than `@Dependent`, the container automatically detects the problem and treats it as a definition error.