Ensure that the WT_CURSOR::uri field matches open_cursor URI.

Since we document that is how it works.
Fix which URI is used by schema truncate.
Return error from cursor open.
Remove lsm=(merge_threads) configuration option.

It's been replaced by lsm_manager=(worker_thread_max). Update
all places it was used in our tree, and add note to upgrade doc.
Don't assign WT_ITEMs in example code, some WT_ITEM fields are private.
Whitespace.
Simplify __wt_connection_close(), there's no reason for it to have the
loops to discard extension handles.
typo
The boundary-next field points to the next boundary structure we were
going to use, but there's no requirement that value be incremented
before reconciliation updates the structure it points to, that is,
there's no guarantee elements of the next boundary structure are still
unchanged. Be defensive, clean up the "next" structure as well as the
ones we know we used.  Reference #1239.

Minor cleanups to clean out the structure more completely.
whitespace
whitespace
Quit trying to clean up the boundary structures on exit, instead
initialize each boundary array element right before it's about to
be used. This is probably slightly more work, but it's less likely
to break in the field, the code to allocate a new boundary item
has to be correct otherwise we'd hit the end of the array and drop
core. Reference #1239.
Merge pull request #1241 from wiredtiger/initialize-boundary-at-use

Reconciliation boundary initialization cleanup.
Merge branch 'develop' into cursor-uri-protect
Trivial simplification, we don't need a local variable.
Don't ignore error return from WT_CURSOR.close (it might be a panic).
Merge pull request #1235 from wiredtiger/cursor-uri-protect

Cursor uri protect
Don't drop core if we fail to allocate the WT_BLOOM structure (jump to
error lable will indirect through bloom).
Leave the returned bloom structure reference set to NULL on error.
When opening simple tables, the table code calls the cursor open
function recursively (on the underlying data source), in which case the
application's URI has already been copied, don't copy it again and leak
the memory. Reference #1234, #1235.
Make text match example.
Merge pull request #1238 from wiredtiger/remove-merge-threads

Remove lsm=(merge_threads) configuration option.
Keep backward compatability in LSM metadata parsing.

Refs #1244