Fix build warning in wtperf.
Fix typo when closing config_parser handle, complain if the
config_parser.close method errors.
Allow overlapping strings when setting a buffer's contents, it's not
insane __wt_buf_set might be used to shuffle strings in an existing
WT_ITEM buffer.  Reference #881, but this doesn't close it, we still
want to understand why it can happen.
Coverity fixes.
Add some comments and fix some style.
Fix bug finding table count with multiple tables.
Don't create an illegal config string.
Merge branch 'develop' into lsm-fixes