Memory interface to join

In the chaining of join operations, the key values are moved to memory, as a simple linked list of records. Theinpu an output thread synchronize with the pause return status. Simple, 50 lines of fode, just counting by record number in a one way flow for output or input. But this simple trick allows chaining, stacks of join operations sifting, each other, really. There is little separation of data and code, the join almost symmetric.