* Added support for async transfer of language code from main to renderer process
  * Added availableLanguage support to about*.html files
  * Added language request for about* pages

  * Added fr-FR selection choice in menus and about pages
  * Added reviewed fr-FR language locale

TODO:

  * Determine a method of configuring availableLanguages meta tag in
    about*.html files without manually modification.
  * Modify preference page to automatically show available languages in selection

…ation

  * Send language codes to web pages to avoid head.meta.availableLanguage changes
  * Modified about*.html files to accept language codes and modify head.meta.availableLanguages
  * Added language labels to en-US/preferences.properties
  * Added language codes to app/locales.js
  * Modified General Preferences tab to use passed language list in Select form element
  * Updated tools/downloadLanguages.js with language constant support
  * Added all languages which have translations

  * Language downloads
  * Re-factoring
  * Merge master

Merge branch 'master' into language-merge