Add support for open-cursor count statistics in both the connection and
data-handles.  This requires atomic update versions of a couple of the
stat macros.
We can dump "lsm:" statistics as well as "file:" statistics, which is useful
for Basho/Riak benchmarks.
Merge pull request #516 from wiredtiger/stats

Add a statistic that counts open cursors and enable logging of LSM statistics