v0.6

Removed obsolete C-style logging function
Replaced std::function with Callable template arguments, improving performance
Replaced Travis CI with GitHub Actions

v0.5

Added configurable logger instance per thread using the global logger as fall-back
Renamed global logger instance LOGGER to DEFAULT_LOGGER
Fixed some advanced clang compiler warnings

v0.4

Added logging to arbitrary wostreams
Added functions for lazy logging, skipping formatting if log level will not be printed
Added building of both shared and static libraries
Added (un-)install targets

v0.3

Simplified multi-threaded logging
Fixed crashes in multi-threaded logging
Fixed build errors on various platforms