context check interceptor: simple attribute predicate

[Tom Zeller]

>> This is another case where we probably need to expose an unfiltered set
>> and allow logic based on that so avoid cases where you might have to
>> "release" something you don't really need or want to release.

Misagh,

Would you be willing to create an issue in JIRA ? Maybe : "Provide an
un-filtered attribute context". The un-filtered attribute context
should probably be located near the filtered attribute context in the
context hierarchy.

Thanks.