doc: typo in Base.group_install().
removed unused imports in base.py
translation: added mo files generation and including them in rpm package
refactor: replaced type comparisons with isinstance
translation: show relative path in generated pot file
removed redundant word from persistor translation
translation: updated .pot file and fetched fresh .po files from transifex
added gettext as a build dependency  for translation files
refactor: move out main._main()'s inner error handlers.
logging: do not log IOError tracebacks in verbose mode.

Related commit 1ec35442 does the same in plugins.py.
main: log IO errors etc. thrown even during Base.__exit__.

Related: RhBug:1077173
tests: simplify the traceback logging.

The previous version was too ambitious runing main() which unfortunately
had side effects on the file system for the running user. It also called
base.logging.presetup() that added handlers to the dnf logger (shared
across test cases).
persistor: do not save Groups if it didn't change (RhBug:1077173)
remove: unused trashy methods in dnf.yum.misc.
tests: fix locale independence.
including .mo files correctly
comps: _by_pattern() no longer does the comma splitting.

In no universe was that a wise thing on this level.
fixed not including .mo files