Reduce the leaf page size from 1MB to 32KB.
Change format test to focus on smaller key/value items.
Don't drop core if the maximum value is smaller than min + 20.
imported patch compact-test-fix
Merge pull request #950 from wiredtiger/reduce-leaf-page-size

Reduce leaf page size
Check that we don't try to discard pages that are splitting.
The posix_fallocate call on Linux is corrupting already written data,
add locking around it and the ftruncate call when either are being
used to extend the file in chunks.

Add configuration support for the Linux-specific fallocate() call, it's
the only one that doesn't appear to corrupt already written data.
Missing WT_RET(), don't lose the error.
Don't try and extend the file unless we have a valid offset.