Adendum to the 0.2 roadmap

- Bugfix: lock to avoid editing General category.
- Bugfix: Remove html characters and new line in the titles of the entries.
- Bugfixes: When importing and exporting feed lists (thanks Jcasas!).
- Bugfixes: Many bugs that emerged during development of this new version (thanks again Jcasas!).
- Improvements: entries obtention thread, the script to launch the app
meets now the LSB, icons contextual category (open/closed category folders), positioning the top of the list when a feed is selected, the size of the list of feed's window now gets saved, keyboard accelerators were 'common-sensed'.
- Script to update the database format.
- Preferences dialog has been restructured.
- Finally, we have implemented more threads in other processes (in instance, the import feeds function; no more blocking!).