logger work: set_loglvl_{action,desc} - execute action on fitting loglvl, backends got names, comment and code cleanups, unit_tests
logger work: set_loglvl_{action,desc} - execute action on fitting loglvl, backends got names, comment and code cleanups, unit_tests

daringer/mmorecpp,daringer/mmorecpp,daringer/mmorecpp