Lint fixes for man page

Summary: See rrh code review: https://github.com/facebook/hhvm/commit/e32f5bf0cc7a74d671c6922108c68bfbdfdbe1f4

Thanks rrh

Reviewed By: @fredemmott

Differential Revision: D1481918
Return false in fscanf if the file is empty

Summary: This will fix #3352.
Closes https://github.com/facebook/hhvm/pull/3364

Reviewed By: @LiraNuna

Differential Revision: D1478505

Pulled By: svcscm
hphp: placate newer clang regarding non-local lambda expressions

Summary: * hphp/hhbbc/test/type-system.cpp: Several non-local lambda
expressions needlessly used [&] ("capture-default").  Remove
the "&".  Here's a sample diagnostic:
  hphp/hhbbc/test/type-system.cpp:169:44: error: non-local lambda\
    expression cannot have a capture-default
  auto const test_empty_array = folly::lazy([&] {

For reference, here's the relevant part of the standard:
  C++11 [expr.prim.lambda]p9:
    A lambda-expression whose smallest enclosing scope is a block scope
    is a local lambda expression; any other lambda expression shall not
    have a capture-default or simple-capture in its lambda-introducer.

Reviewed By: @alexmalyshev

Differential Revision: D1482394