Updated Translations
New translation-codes for the i18n-directory. Related to issue #9. Removed translations: ast,eo,eu,fa,ka,oc because there are no offical languages in ISO-3166-1 alpha-2.
Updating method get_variable for issue #17

Added a check for the method get_variable, because the fixed issue #17 (proxy support) need this. This check is needed because the variables 'proxy_user' and 'proxy_password' are optional.
Updating last commit, merged issue #17 and issue #10

A better idea to remove the little bug in issue #17. I have merged issue #17 and issue #10 for overview. The idea for the solution for issue #17 is from carmenates09.
Merge remote-tracking branch 'upstream/master'

Conflicts:
	apt-mirror
Added proxy support

Original change comes from GitHub-User <<carmenates09>>/<<apt-mirror>>@<<01833f2adf4a14ed14ef32ac0d85790826947119>>
Added default variables for 'proxy_user' and 'proxy_password' because this variables can be empty
Merge pull request #31 from EifX/master

Added Proxy support