PLXCOMP-222 LEF flag set for UTF-8 encoded names.
[PLXCOMP-178] Last modified time preservation

Patch by David Tombs, applied unmodified
Updated plexus
[maven-release-plugin] prepare release plexus-archiver-2.4.4
[maven-release-plugin] prepare for next development iteration
Converted to commons-compress for all archivers, upgraded to cc 1.8.1

Please note that there are still some auxilarry functions that could also be converted.