Fix a few issues that showed up in an hg build

Summary: "fbconfig -r hphp && fbmake dbg" in a mercurial checkout
now runs without any warnings

Reviewed By: @alexmalyshev

Differential Revision: D1684337

Signature: t1:1684337:1416217066:2f77224da83c0b654f82dfc29534affca7a35b02