This commit changes Open() to provide an additional Options argument. The options
argument currently only has a Timeout which will cause the Open() to return
ErrTimeout if a file lock cannot be obtained in time.
Fixes#207.
The count and overflow columns are meaningless for freed pages since
there could be random overflow data in there. This commit removes those
columns for free pages.
Well, this is embarassing. Somehow the freelist was never getting written after each commit.
This commit fixes that and fixes a small reporting issue with "bolt pages".
