Check the block header checksum before we clear it, it should be
the same as the passed-in checksum, and if just those 4 bytes are
corrupted, we wouldn't noticed. SERVER-16457.
Merge pull request #1491 from wiredtiger/block-header-checksum

Check the block header checksum before we clear it.
Windows Build fix
snprintf - Implement a custom version of snprintf match the
truncation behavior of C99 standard snprintf until MSVC supports snprintf.
Merge pull request #1492 from markbenvenuto/win_build_fix

Windows Build fix
Merge pull request #1493 from markbenvenuto/snprintf_fix

Windows - Implement a custom version of snprintf
Stop maintaining a separate Windows version of the file list, generate it
from the POSIX list (it shouldn't change that often).
Clarify that setting statistics_log.wait to non-zero value starts the
statistics logging.
Add a Windows-specific file, os_win/os_snprintf.c.