Back-shell still doesn't support binary data, should use -lldif routines

 (on Linux), with max_concurrency set to 0 (as many as needed), 1, 2,
and 3.

in attempt to get it work with GNU PTH.

macros LUTIL_STRDUP and friends).

l is already parsed?

Plus more pthread rwlock code

Update comment with reference to publically available examples.

Copyright 2000 Stig Venaas, UNINETT
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