Create a "metadata" cursor.
When splitting a page, if the original WT_REF key was not instantiated, take a copy of the (whole) first key from the leaf page.

refs #656
commit
Merge branch 'develop' into split-with-disk
Fix error handling when splitting skiplists: don't update anything in the original tree, or install the insert in the new page, until after all failing operations have completed.

refs #656
Update some comments.
Use the first (full) key from the leaf page in the new split-merge parent.
Don't try to copy the key from the parent: split-merge pages need full keys.

refs #656
comment
comment
Don't touch the page modify structure for in-memory splits: just swap the page into place directly.

refs #656
Make sure unlocking the parent ref is the last thing we do in a split.

refs #656
Merge pull request #660 from wiredtiger/metadata-cursor

Add a public "metadata:" cursor.
Merge pull request #656 from wiredtiger/split-with-disk

test/format failure: checkpoint ranges never verified. In memory page splits were over writing references to previous page splits. Causing us to skip freeing those blocks.