Clarify annotation collection with applicators

In particular, "contains" collects annotations.  I'm not sure
where the exception came from, as it was not present in the
previous draft (to the extent that that draft mentioned
annotations).

The CREF actually did talk about annotation collection so
apparently this was a bit of a muddled mess anyway.

This makes "contains" behave like all other applicators,
producing both assertion and annotation results.

Author: handrews

jsonschema-core.xml

@@ -654,7 +654,10 @@
             <t>
                 Evaluation of a parent schema object can complete once all of its
                 subschemas have been evaluated, although in some circumstances evaluation
-                may be short-circuited due to assertion results.
+                may be short-circuited due to assertion results.  When annotations are
+                being collected, some assertion result short-circuiting is not possible
+                due to the need to collect annotations from all subschemas, including
+                those that cannot further change the assertion result.
             </t>
             <section title="Keyword Interactions">
                 <t>
@@ -1981,6 +1984,8 @@
                         <t>
                             An instance validates successfully against this keyword if it validates
                             successfully against at least one schema defined by this keyword's value.
+                            Note that when annotations are being collected, they MUST be collected
+                            from all subschemas if any subschema validates successfully.
                         </t>
                     </section>
 
@@ -2245,16 +2250,10 @@
                         </t>
                         <t>
                             An array instance is valid against "contains" if at least one of
-                            its elements is valid against the given schema.  This keyword
-                            does not produce annotation results.
-                            <cref>
-                                Should it produce a set of the indices for which the
-                                array element is valid against the subschema?  "contains"
-                                does not affect "additionalItems" or any other current
-                                or proposed keyword, but the information could be useful,
-                                and implementation that collect annotations need to
-                                apply "contains" to every element anyway.
-                            </cref>
+                            its elements is valid against the given schema.  Note that when
+                            collecting annotations, the subschema MUST be applied to every
+                            array element even after the first match has been found.  This
+                            is to ensure that all possible annotations are collected.
                         </t>
                     </section>
                 </section>

jsonschema-validation.xml

@@ -1220,9 +1220,9 @@
                         their results, without asserting any conditions of their own.
                         Without assertion keywords, these applicators can only cause assertion
                         failures by using the false boolean schema, or by inverting the result
-                        of the true boolean schema.  For this reason, they are better defined
-                        as a generic mechanism on which validation, hyper-schema, and extension
-                        vocabularies can all be based
+                        of the true boolean schema (or equivalent schema objects).
+                        For this reason, they are better defined as a generic mechanism on which
+                        validation, hyper-schema, and extension vocabularies can all be based.
                     </t>
                     <t hangText='"dependencies"'>
                         This keyword had two different modes of behavior, which made it