Msgcheck

Changed

- **Breaking**: rename some long names for command line options
- Use codecs module to unescape strings (faster with python 3)
- Add short option synonym `-P` for `--pwl`
- Add short option synonym `-e` for `--extract`
- Major code cleanup: add comments, move checking/error functions from class PoMessage to class PoFile
- Full PEP8 compliance

Fixed

- Fix problem when latest string in file has a plural form (this last translation was ignored)
- Display full exception in case of problem when reading file

Added

- Display number of files OK when there are multiple files checked and no errors

Added

- Add short option `-m` for `--onlymisspelled`

Added

- Add option `-d` (or `--dicts`) to use extra dictionaries for spell checking

Added

- Add option `--onlymisspelled` to display only misspelled words instead of errors with translations

Added

- Add option `--extract` to extract translations