Remove empty lines from /etc/locale.gen
Simplify locales configuration on Ubuntu

- Generate only en_US.UTF-8 (not en_US) locale, as for Debian
- Use update-locale to configure /etc/default/locale configuration
- Remove localedef, since locale-gen compiles the locales specified
Set default LC_CTYPE and LC_COLLATE environment variables
Export LANG, LANGUAGE and all LC_ environment variables
Merge pull request #447 from ar-jan/locales

Improve locales consistency