Make sure that we actually clear the page table, not just pretend to!
Proper read/write locks on getting snapshot from journal file
Merge branch 'voron' of github.com:ayende/raven.voron into voron
Changing the way we are handling headers files.
We'll use direct I/O to handle them, instead of relying on mmap files.
Will also force a flush on write.
Exposed both large & fine grained API for handling this.
LOTS of changes, and probably non working code.
The basic idea is that I am going to do the following:

1 file memory mapped as scratch. I create it with Temporary | DeleteOnClose. All pending writes go there.
journal files are written to as before (write_through, unbuffered), but never read from during normal operations.
Writes to the data file are done via mem map, with occasional fsync.

Need to re-write backups, and no tests were ever run.