Changes for observert_ptr for C++98/03 and higher.

0.4.0 2019-05-30

Use dashes in unit name for vcpkg

0.3.0 2019-05-03

Improved support for CMake and Conan and contains numerous other changes and fixes.

0.2.0 2016-02-10

Expanded ordered comparison of related types to pre-C++11 usage of GCC through the use of __typeof__.

0.1.0 2016-02-08

Added ordered comparison of related types through the use of common_type.

0.0.0 2015-11-12

Initial release.
