installing more than one language should be possible

changing asterisk::language to a define will let us install more than
one language package, plus it's now possible to iterate over languages
like this:

asterisk::language { language => ['es', 'de', 'fr-armelle'] }

Signed-off-by: Gabriel Filion <gabster@lelutin.ca>
Update language list.

Taken from debian packages.

'it' not included since it's a dummy transitional package to
'it-menardi'.

Signed-off-by: Gabriel Filion <gabster@lelutin.ca>