Revert "SERVER-7378 Prevent WRITETODATAFILES and FlushViewOfFile from running at the same time"

This reverts commit 5352345eda2ffa24a72af1d5bbaccaa32bcb1006
SERVER-9482 add flag to enable activation of FIPS mode (off by default)

(cherry picked from commit 81676bfa36c68b1247f0e08b666e33c3e3875755)

Conflicts:
	SConstruct
Merge remote-tracking branch 'upstream/v2.6' into v2.6