Bug 24262: Translate installer data in YAML format

Bug 24262: Translate installer data in YAML format

This patch adds the ability to:
1) Create new translation files from yaml installer files
2) Create installer directory for a given language

It will not create a installer directory if it already exists.

New (possible) translation files:
  xx-YY-installer.po
  xx-YY-installer-MARC21.po
  xx-YY-installer-UNIMARC.po

Needs Bug 13897 (for yaml files)

NOTE: updated version adding ability to process multiline
fields, discard small ( < 2) strings, and discard strings
with pure html, TT or punctuation.

To test:
1) Apply patches from Bug 13897
2) Apply this patch
3) Go to misc/translation
4) Create translation files for a NEW language
   $ ./translate create xx-YY

   check new file 'xx-YY-installer.po'

5) Copy ../../installer/data/mysql/en/optional/auth_val.yml
   into ../../installer/data/mysql/en/marcflavour/marc21/mandatory/
   and ../../installer/data/mysql/en/marcflavour/unimarc/mandatory/

   remove po/xx-YY*, then repeat creation

   check new files 'xx-YY-installer.po', 'xx-YY-installer-MARC21.po'
   and 'xx-YY-installer-UNIMARC.po'

   remove all new files

6) Create for xx-YY again and try update
   $ ./translate create xx-YY
   edit ../../installer/data/mysql/en/optional/auth_val.yml
   and change one char in one of the translatable values,
   also edit 'xx-YY-installer.po', translate the same
   string (in msgstr).

   Do an update
   $ ./translate update xx-YY

   check in 'xx-YY-installer.po' a fuzzy value for the
   translated value and the preservation of the translation
   Fix the translation, or add a new one.

7) Create an install dir for xx-YY
   ./translate install xx-YY

    Check new dir '../../installer/data/mysql/xx-YY/'
    Check files on it
    $ tree ../../installer/data/mysql/xx-YY/
    and compare with ../../installer/data/mysql/en/

    All installation files must be present

8) Try a new Koha install using this language in the
   usual way.
   Check in authorised_values table for the translated string.

9) Try create an install dir for an existing language
   (eg. es-ES, de-DE or fr-FR ), eg.
   ./translate install de-DE

   Install dir is detected and not changed, a note is printed.

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