Display the failed open path, it makes debugging easier.
Make sure all chunk involved in a merge have Bloom filters.  Fix a race where a chunk is merged and removed from the tree during creation of a Bloom filter.

refs #809
Have LSM compact logic match regular merges exactly: always create Bloom filters first.  If there are any concurrent reads in the tree, they will benefit from the Bloom filters, and this avoids having different paths through the merge code.
Switch || to && to fix build.
Merge pull request #887 from wiredtiger/merge-bloom-fix

Make sure all chunks involved in a merge have Bloom filters
Fix another bug regarding when pages can be evicted: have reconcilition track the maximum transaction ID on the page (regardless of whether it is skipped).  A page can only be evicted when it is clean and has no updates that are too new.

refs #884
Rename disk_txn to reflect what we're actually using it for.
Add comments explaining the reconciliation transactional read logic, including when pages become clean.
Merge pull request #888 from wiredtiger/rec-skip-clean

Fix a bug regarding when clean pages can be evicted
Loosen the assertions around LSM merges and Bloom filters: it's okay to merge chunks in generations greater than zero even if they don't have Bloom filters.
Remove the assertion that every chunk being merged has a Bloom filter: under load, creating a Bloom filter can fail and retry, so we can't guarantee that all Bloom filters are created in order without more effort.
Don't use memory after we've freed it.
Merge branch 'develop' into evict-walk-hazard