Refactor test/.../poller.cpp to use Catch
Merge branch 'master' into feature/refactor_poller_test

* master:
  Refactor test/common/evbuffer.cpp to use Catch
  Fix 74ba78bc4674e..., which was wrong
  test/.../socket_valid.cpp: increase comment clarity
  common/utils.h: improve invalid-socket-value normalizers docs
  common/utils.h: more love for the explanatory comment
  common/utils.h: improve and reword comment
  common/utils.h: no need to define IGHT_SOCKET_MAX
  Ensure that IghtConnection(fd) checks on fd work OK
  Add unit test for socket-validity code
  common/utils.h: better checks for invalid sockets
  utils.h: remove long-long-related check
  log: make libight quiet by default
  utils.c utils.h: don't include twice headers
  common/utils.h: add ifndef-define-endif guards
  common/utils.h: add libight's copyright
  Merge net/ll2sock.h into common/utils.h
  net: stop using `long long` to represent sockets

Conflicts:
	test/common/include.am
	test/include.am
remove unneeded include.am