Fix CLI regressions (see below for details)

Fix CLI regressions (see below for details)

This is a combination of the test suite improvement fbc1648 and the frontend changes in 414aec5..ee8abd6.

* Harmonize extraction keyword parsing between distutils and standalone CLI (#388, #384, #311)
* Don't use unicode-variant %r for logging
* extract: don't die badly when no input paths are specified in optparse mode
* Remind the optparse CLI about `extract -s` (a shorthand for `--strip-comments`) (#390)
* Teach the optparse CLI about the parameter aliases it had forgotten in #311 (#390)