Latest xml files

Here are the latest wsdl and schema files for WS-CTX.  They are now in
line with the spec.  Notable changes are:

- Removal of address type from the body of messages.  Addressing is
completely handled by a context header.

- Removal of the Completion status type and messages.

- Removal of ALS

- Changing of ActivityService to ContextService and UserActivityService
to UserContextService.  NB The spec refers to UserContextService as
UserCTXService (this should be changed)

- Introduction of the ServiceRef type for addressing.

- Addition of the optional ctx-manager element to the context structure
for pass-by-reference contexts.