- Overrides added
- usages of push_back() replaced with emplace_back()
- Loop variable made const-refernce
- NULL replaced with nullptr
- Names used in the declaration and definition unified
- size() replaced with empty
- Identical cases merged
This also goes for pkg-config installed by our CMake installation.
This includes
* Updating CMake version on Travis
* Adding a `Catch2` subfolder to the `single_include/` folder to
provide this include path both _inside_ the repository, and _outside_.
* Updated examples to build with the new paths
* Other general CMake cleanup