fixed: multiplexing deadlock
re-openable hashjoin integration test
Changed memory segment to use "unsafe" (native) memory accesses.
Mapped normalized key comparisons and record swapping in sorters to memory segment operations.
Fixed erroneous normalized key generation in PactCharacter.
Removed obsolete denormalizable key types.
Added bulk copy methods to memory segment.
Updated bulk get/put methods in memory segment in support of unified nephele/pact memory buffers.