* changelog: update changelog for v2.1.3
* update version in metadata
* changelog: fix formatting issue and release date
* appstream: update release date
* Getting ready for 2.1.
* Fixed version.
* Year.
* Manually added line as takase said to.
* Fixed minor issue at takase's behest.
* Dunno where that went.
* Updated to use a function pointer.
* OK, as discussed, adding this manually for now.
* Updated SDL.
- Added version and license metadata
- Configuration data to be used in configured files to set metadata
- Portable binary and directories in the main install directory
- Binary file installed in correct places for all supported platforms
- Freedesktop AppStream support
- Added missing files install rules