API additions: table_setn, table_addn, table_mergen... for speed!

POOL_DEBUG support for correctness.

Submitted by:	Dmitry Khrustalev <dima@bog.msu.su>, Dean Gaudet
Reviewed by:	Brian Behlendorf, Jim Jagielski


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/1.3.x@80025 13f79535-47bb-0310-9956-ffa450edef68