Bug 18688: Warnings about UTF-8 charset when creating a new language

Bug 18688: Warnings about UTF-8 charset when creating a new language

This patch removes some warnings when creating new languages,
those related with uft8 and two not related.

Tipical messages are:
>Warning: Can't determine original templates' charset, defaulting to UTF-8
>Warning: Charset Out defaulting to UTF-8
>...
>Removing empty file /../xx-YY-marc-NORMARC.po
>I UTF-8 O UTF-8 at /../kohaclone/misc/translator/tmpl_process3.pl line 365.
>Use of uninitialized value $pref_name in concatenation (.) or string at /.../misc/translator/LangInstaller.pm line 197.
>Created /../misc/translator/po/xx-YY-messages.po.

First four are 'normal' messages
The fifth one correspond to an unquoted preference string
The sixth one is a normal output message from msgint command
We will hide them unless verbose '-v' option is selected,
and fix the error.

To test:
1) Go to misc/translator
2) Create new language files
  $ perl translate create xx-YY
3) Check warnings and messages
4) Apply the patch
5) Remove created files, and create them again
   Ther must be no messages
6) Repeat 5) with verbose option '-v', check
   old messages

7) BONUS: without the patch update a language,
   for example de-DE:
   $ perl translate update de-DE
   Note (git status) a new file, po/de-DE-messages.po~
   This is a backup file from msgmerge command
   With the patch this backup is removed.

Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>