Copy the OXID_INFO from the stub manager, if available, in 
proxy_manager_construct. Otherwise, attempt to resolve it.

Use ipidRemUnknown from OXID_INFO in the proxy manager instead of 
magically generating the IPID for RemUnknown.

rpcrt4: Implement associations which are intermediary objects that track the relationship between the client and a given endpoint on the server.

Use these to encapsulate the connection pool so that the lifetimes of 
connections are properly handled again.

The tests shows that CBGetTextAreaHeight was using a bad formula.

Debugged by Anastasius Focht.