SERVER-9411 SERVER-9678 Fix windows failure.

This change just reduces the number of open files by doubling the memory
limit for the failing test. The long-term solution will be to call
_setmaxstdio(2048) at startup on windows.
SERVER-9411 Fix IO error messages from sorter on windows.
SERVER-8741 make sure we contact from-shard at least once after commit
SERVER-9518 Include necessary header in hash_namespace.h