Create Bloom filters whenever waiting to do a merge.  Remove the 'lsm_bloom_newest' configuration, since this change makes it redundant.

refs #591
Merge branch 'develop' into lsm-bloom-newest
Merge branch 'develop' into lsm-bloom-newest
Fix error handling in backup cursor open.

Without this change test_backup03 hangs occasionally, with this change it
reports an error instead.
Always use the chunk flags to check for Bloom filter existence.  Sometimes chunk->bloom_uri is set before the Bloom filter has been populated.

refs #591
Fix a long-standing deadlock that could happen when closing a busy LSM tree.

The fix involves spinning on the schema lock and having LSM worker threads inherit the "schema locked" flag when they are shutting down.

refs #349
Review %d format usage, fix where it should have been something else.
Merge branch 'develop' into lsm-bloom-newest

Conflicts:
	src/cursor/cur_stat.c
	src/include/schema.h
Keep lint quiet.
LSM uses "long" variables, and prints them, stop s_style from complaining.
If we set the WT_UPDATE/WT_INSERT forward pointers before calling the
serialization function, we can potentially avoid the additional memory
barrier inside the serialization function.
Merge pull request #591 from wiredtiger/lsm-bloom-newest

Automatically create bloom filters if merges stop. This branch also fixes some long standing races between LSM and schema level operations.
lint
spelling
Remove "lsm_bloom_newest" from the wtperf medium LSM config -- it is now on by default.
We have to use the update value approved by __wt_txn_update_check, copy it
into a local variable before we verify it.
Merge pull request #718 from wiredtiger/serial-barrier

avoid memory barriers inside serialization functions.
Always set up next pointers before calling insert_serial.  Never search inside the serial lock: if the configured insert isn't in the right place, restart the operation.

Follows on from the changes in #718
Simplify the col_append serial function -- make it closer to a normal insert.
Fix the test for empty skiplists.

refs #719