It's non-standard to have multiple usage statements for incompatible options,
reduce to a single usage statement; complain and fail if incompatible options
are specified.  Reference #740.
Add a mention of the JSON dump format to the Ref Guide, reference #740.
Reset cursors on auto-commit failure, reference #672.
Fix max_latency config units.
Update the LSM throttle calculations.

* We were using the wrong check to see if any chunks had been checkpointed
  in the current tree.
* A couple of other updates for readability.
Remove unused loop variable.
Fix a bug in recovery with missing files (e.g., after a hotbackup that raced with file creation).

refs #1042
Merge pull request #1044 from wiredtiger/lsm-throttle-tune

Improve LSM throttling.
Fix a bug just introduced to LSM. Only look at on disk chunk if it exists.
Exercise all isolation levels in test/format.

motivated by reviewing #1040
Merge branch 'develop' into auto-txn-reset-cursors
In test/format, split out the session configuration from isolation: the latter is used to write RUNDIR/CONFIG.
whitespace, spelling
In auto-commit operations, don't reset cursors if we are going to retry the operation.

refs #672, #1040
Merge branch 'develop' into auto-txn-reset-cursors
Doc typo: there is no need for "::" after a structure name.
Merge pull request #1040 from wiredtiger/auto-txn-reset-cursors

Cursors should be reset after an auto-commit failure.
Missing breaks in switch, we were only running with isolation=snapshot.
Avoid a "maybe uninitialized" warning.
Add more detail about our JSON output, along with a small sample. refs #740.