[www-client/firefox-l10n-*] introduce scripts and eclass

Files to manage separate language packs for Firefox.

- firefox-l10n.eclass
- ebuilds-new-version-Firefox-l10n.sh - install ebuild for the new
  version
- install-Firefox-l10n.sh - install the packages on system
Merge pull request #6 from Sabayon/firefox-l10n

[www-client/firefox-l10n-*] introduce scripts and eclass