common: stop importing std::{bind,ref,cref} into namespace ndn

And reduce the usage of std::bind() throughout the codebase.
C++14 lambdas are easier to understand for humans and more
likely to be optimized by the compiler.

Change-Id: Ia59fad34539710f8801c52914896ce426fb7e538
diff --git a/tests/unit/mgmt/status-dataset-context.t.cpp b/tests/unit/mgmt/status-dataset-context.t.cpp
index 58c8382..6d1e0b9 100644
--- a/tests/unit/mgmt/status-dataset-context.t.cpp
+++ b/tests/unit/mgmt/status-dataset-context.t.cpp
@@ -229,13 +229,7 @@
 class AbnormalStateTestFixture
 {
 protected:
-  AbnormalStateTestFixture()
-    : context(Interest("/abnormal-state"), bind([]{}), bind([]{}))
-  {
-  }
-
-protected:
-  StatusDatasetContext context;
+  StatusDatasetContext context{Interest("/abnormal-state"), [] (auto&&...) {}, [] (auto&&...) {}};
 };
 
 BOOST_FIXTURE_TEST_SUITE(AbnormalState, AbnormalStateTestFixture)