1. Changed BTree code to use the new IBufferCache and IStorageManagerInterface to cleanly deal with the lifecycle of files.
2. Identified possible bug in BufferCache related to flushing pages when file reference count reaches zero. Code will compile but some tests fail. To be fixed next.

git-svn-id: https://hyracks.googlecode.com/svn/branches/hyracks_storage_cleanup@254 123451ca-8445-de46-9d55-352943316053
43 files changed