Honor the WT_DHANDLE_EXCLUSIVE flag in LSM: get exclusive access to the tree during salvage, etc.
Don't drop old LSM chunks during a hot backup
Remove workarounds from test/format for logs and LSM.

refs #972, #976, #979
Store the wiredtiger_open configuration when a database is created, so that settings like cache size, extensions and logging are set consistently by all subsequent users of the database.
Add documentation for the `WiredTiger.basecfg` file.
Fix a warning:
src/conn/conn_api.c:687:3: error: format not a string literal and no format arguments
Merge branch 'develop' into lsm-logging-fixes
spelling
Before test/format runs salvage, it takes a copy of files.  Do that before opening the database, so the files are stable on disk.
Merge pull request #998 from wiredtiger/lsm-logging-fixes

LSM logging fixes