This fixes the linux/gcc error building Google Test with gcc 4.7:

https://travis-ci.org/github/jbeder/yaml-cpp/jobs/668233706

Add check that a move assigned Node gets the same representation as the
moved-from Node had before the move.

It's clearly related to an existing node, so it can have a mark and give
an error location.

This commit updates the version of Google Test from 1.8 to 1.10.

The explicitly defaulted or implemented move constructors and assignment
operators are made "noexcept".

Bugfix:
* src/stream.cpp Stream::Stream() char_traits::int_type intro[4] is
  now aggregate-initialized (to zero) to avoid UB.

Minor changes:
* Using std::isinf() and std::signbit() instead of comparing for
  equality with infinity.
* src/streamcharsource.h: Added #include "stream.h".
* src/stream.h: Forward declaring "class StreamCharSource".
* Some implicit casting changed into static_cast's.

Signed-off-by: Ted Lyngmo <ted@lyncon.se>

This is in preparation for other patches that will make use of the
macro. The patch also removes #undef:ing the macro after its been
used to not make the header inclusion order critical. Otherwise,
the new header would always have to be the last of the yaml-cpp
headers to be included.

E.g. `!2`.

Change the namespace from yaml::yaml to yaml-cpp::yaml-cpp.

Also add a test for a parser with no data

This happens whenever in a macro you use some "if" block, and don't use curly braces {},
as the macro is expanded on a single line, not on several lines. So just add the missing
curly braces to please gcc.

In file included from /remote/users/mlamesch/CloneFromPlatinum/yamlcpp/osp/Yamlcpp/18-0-0-5/include/yaml-cpp/yaml.h:18,
                 from src/TestYaml.cpp:2:
/remote/users/mlamesch/CloneFromPlatinum/yamlcpp/osp/Yamlcpp/18-0-0-5/include/yaml-cpp/node/convert.h: In static member function static bool YAML::convert<int>::decode(const YAML::Node&, int&):
/remote/users/mlamesch/CloneFromPlatinum/yamlcpp/osp/Yamlcpp/18-0-0-5/include/yaml-cpp/node/convert.h:139:1: error: this if clause does not guard... [-Werror=misleading-indentation]
 YAML_DEFINE_CONVERT_STREAMABLE_SIGNED(int);
 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

* Showing test output only on failure

* Test commit to see the failed test

* Now making sure that the tests pass with no output

🐛 Fixes #748 (#770)

Also run clang-format on these files as requested

Add empty list of sources to add_library and add_executable.

The generator expressions here are actually unnecessary, now that I think about it.

This should fix #745

Example of how someone might consume yaml-cpp with bazel:

cc_binary(
    name = "example",
    srcs = ["example.cc"],
    deps = ["@com_github_jbeder_yaml_cpp//:yaml-cpp"],
)

Remove 2.6-isms
Remove 2.8-isms
Bump CMake minimum version to 3.4

Disable some options when used as a subdirectory

Use `CONFIGURE_DEPENDS` with `file(GLOB)` when possible

Backport CMake 3.15's MSVC_RUNTIME_LIBRARY setting.
Set all compile options as generator expressions.
Set all find-package files to be installed to the correct file.

Remove `export(PACKAGE)`, as this has been deprecated.
Remove fat binary support
Remove manual setting of iPhone settings. These should be set by parent
projects.
Remove use of ExternalProject for a local use
Conditionally remove format target unless clang-format is found

* CMake: Prefix options with "YAML" and hide platform-specific options

When including yaml-cpp as a subproject, some option names can conflict with other projects.

(1) Make sure the yaml-cpp options are prefixed with YAML
(2) Hide platform-specific options when possible to avoid cluttering the cmake option list

* Update docs for change from BUILD_SHARED_LIBS to YAML_BUILD_SHARED_LIBS