Merge pull request #6 from l/translation_ja

Update Japanese translations
update German translations
Open HTML/CSS validators in new tab/window
Add missing docstrings, fix pylint warnings
Disable word wrap in name header of scripts table
Remove duplicate import of warn
Use Django tag "url" instead of hardcoding URLs in templates (requires Django >= 1.5)
Add ALLOWED_HOSTS in settings template
Add Travis file
Fix keyword argument for old /info/ URL
Remove extra whitespace in a German translation
Add check of translations with msgcheck (for Travis)
Add missing package libenchant-dev for Travis
Remove obsolete URLs starting with /plugins/
Add hyphen in URLs of scripts by name (for scripts with old API)
Remove column "donation number" in sponsors table (display the donation number after the name)
update Polish translations
Add screenshot from zphinx
Add category for screenshots, add screenshots of glowing-bear and weechat.el
Fix PEP8 compliance (line too long)