Move legacy CDB code used only in unit tests into test area. Fix column
width in pmem and comment out the unused case statement (in healthy
tests) from the penciller test code
There was some unpredictable performance in tests, that was related to
the amount of time it took the sft gen_server to accept a cast whihc
passed the levelzero_cache.
The response time looked to be broadly proportional to the size of the
cache - so it appeared to be an issue with passing the large object to
the process queue.
To avoid this, the penciller now instructs the SFT gen_server to
callback to the server for each tree in the cache in turn as it is
building the list from the cache. Each of these requests should be
reltaively short, and the processing in-between should space out the
requests so the Pencille ris not blocked from answering queries when
pompting a L0 write.
Plugged the ne wpencille rmemory into the Penciller, and took advantage
of the increased speed to simplify the callbacks involved.
The outcome is much simpler code
Not yet integrated, but there is now unit-tested module for the new way
of managing L0 memory cache in the Penciller.
This mechansim is considerably more efficient than previous efforts and
should allow for further simplification of the code.
