- Update to version 0.4.6
* A lot of player cleanup and refactoring.
* Ability to choose which audio output backends to include in the
build system: see the cmake script for the relevant WANT_???
options. Player's --help command line switch lists the available
backends.
* Improved pkg-config file generation in cmake script.
* Other minor source clean-ups.
* CMake project clean-ups. Cmake v3.4 or newer is now required.