The following should help most casual users of the project update their applications:
ContextHolder and all of its
    related classes have been removed. This significant change was made for the sake of consistency
    with the core Spring project's approach of a single ThreadLocal per use case, 
    instead of a shared ThreadLocal for multiple use cases as the previous 
    ContextHolder allowed. This is an important change in 0.9.0. Many applications
    will need to modify their code (and possibly web views) if they directly interact with the old 
    ContextHolder. The replacement security ThreadLocal is called
    
    SecurityContextHolder and provides a single getter/setter for a
    SecurityContext.
    SecurityContextHolder guarantees to never return a SecurityContext.
    SecurityContext provides single getter/setter for Authentication.ContextHolder,
    SecureContext and Context to directly call SecurityContextHolder
    and work with the SecurityContext (instead of the now removed Context
    and SecureContext interfaces).Context
    implementations, your applications no longer need to perform checking of null and
    unexpected Context implementation types, and the new SecurityContextHolder
    is an InheritableThreadLocal - which should make life easier in rich client 
    environments.