SERVER-15369 Explicitly write zeros when creating ns files

Backported from commit b39f5ccc3e5c74918c8f2cd46d33c5b6316f4b06
SERVER-15369: Clean up partially created .ns files

    (cherry picked from commit 243f11cd82d7925c77df0b04fad58b18f70cf031)
SERVER-15111 Treat corruption of final journal section as an expected event

Manual backport of the following commits (combined):
8e1f5beabfad09c790e46826e8b3c7dcc5070d8d
6e93b33179e71abce820e534b3d32f1e593f71ca
SERVER-13616 "type 7" (OID) error when acquiring distributed lock for first time
(cherry picked from commit 6254a575a99d9eeda90b0712efd4486411591212)