Don't waste memory when creating or allocating from small, long-lived
APR pools after clearing or destroying pools that allocated larger
nodes.

When allocating nodes from the bucket allocator (<= 80k or 20 pages),
we would eagerly reuse *any* free node that is at least the minimum
size.  Depending on the pool usage scheme, that extra memory would
never be used.  This patch limits the node to approximate twice the
minimum.

* memory/unix/apr_pools.c
  (allocator_alloc): When searching the buckets for free nodes, limit
                     the range to twice the starting index. 


Submitted by: Stefan Fuhrmann <stefan fuhrmann wandisco com>




git-svn-id: https://svn.apache.org/repos/asf/apr/apr/trunk@1594729 13f79535-47bb-0310-9956-ffa450edef68