g11n

There is currently an [open issue](https://github.com/joomla/jissues/issues/73) where @mbabker points out the reasons why it might be good to have the JTracker application available in multiple languages.

I would agree with that completely.

Currently there have been responsible programmers creating about 50 language keys for the JTracker application (about a dozen of them being used) and we also have the "core CMS" language files containing houndreds of strings, not used anywhere.

The rest of the strings used in the application has been hard coded by a group of irresponsible developers (including the one opening this PR...). The reason why ?? I can only speak for myself: I was too lazy ;(

So - I think we have several options to go from here:

#### 1) The J!Tracker remains "english only"

Nothing to do. This issue (and #73) can be closed.

#### 2) Use ini files and ALL_CAPS_LANGUAGE_KEYS

Wait until somebody converts all those hard coded strings to ALL_CAPS_KEYS and spend some lazy evenigs on the creation and maintainance of the language files.

We might wait for that to happen.... or

#### 3) Go crazy...

I might have stated before that I'm a very lazy person. So I like to spend my time creating scripts that do the "ugly work" for me. - Like the creation and maintainance of language files :P

The proposed solution to the above mentioned problem implemnents a (still) experimental language handler, that has not been tested out there in the wild.

The basic idea is:
* Read language files in multiple formats.
* Extract the key/value pairs.
* Store the result in a "permanent cache" to speed things up.

The language file format to use in JTracker will be `po` ([gettext](http://en.wikipedia.org/wiki/Gettext)), the result is stored to a "native PHP array" which is written to a text file. Other options can be explored.

#### 3a) Required changes

Changes to hard coded strings in Twig templates and PHP code:

```php
// template.twig
<label>
    My String

    // change to:
    {{ translate("My String") }}

    // **OR** just use a pipe and a shortcut:
    {{ "My String"|_ }}
</label>
```

In PHP you would use the global function with an easy to remember name; `g11n3t` (*)

```php
echo g11n3t('My String');
```

... and go home !

(*) **btw**: `g11n3t` means `globalizationtext`. If you don't like it, you may create your own alias ;)


The next step would be the creation of the language files.

#### 3b) Language template creation

For gettext files, you first create a **template** that contains all the **keys** and **empty values**.
These templates are used to create and update the localized language files.
The file extension for template files is `.pot`.

```
# Extension.pot

msgid "My String"
msgstr ""
```

These files can be created and maintained manually, however... I'm a lazy person (did I say that before ? )

The gettext utility [xgettext](http://linux.die.net/man/1/xgettext) can read a wide range of code languages and supports a custom function name.
It supports over 20 languages officially, others just "work" (like JavaScript can be parsed as Python...) but the only unsupported language I know is Twig :(
Fortunately this is a [known issues](https://github.com/fabpot/Twig-extensions/blob/master/doc/i18n.rst), so the solution is to compile the templates and then run xgettext over the generated PHP code.

There is a new script that just collects all relevant files and passes them, along with some options, to xgettext:

```
tracker.php make langtemplates
```

Will automatically generate the language templates for the core JTracker application, the JTracker template as well as all the Apps.

Those language templates, once created, are now ready to hand over to the translators or send them to an online translation service (e.g. transifex).

Job finished :)

#### 3c) Localize It !

To actually "see" the site in different languages, you have to create a file that contains the localized strings for every language.
The extension for language files is `.po`.

For example a german language file might look like this:
```
# de-DE.Extension.po

msgid "My String"
msgstr "Meine Zeichenkette"
```

A chinese language file might look like this (google says..):
```
# zh-CN.Extension.po

msgid "My String"
msgstr "我的字符串"
```

and so on...

Translators may notice here, that you always **see** the original in clear text above the translation. -- If you plan to handle the translations manually...

While you can also create those files manually, the gettext tools [msginit](http://linux.die.net/man/1/msginit) and [msgmerge](http://linux.die.net/man/1/msgmerge) can create and update language files from a given template - So why not use them (remember: me lazy...)

```
tracker.php make langfiles
```

will create language files for the core, the template and all extensions (Apps) in all defined languages.

What else ?

#### System requirements

To **manually** create and manage your language file(s) you will need:
* Your hand(s).

To have your language files created and managed **automatically** you will need:
* [gnu gettext](http://directory.fsf.org/wiki/Gettext) - from which you will only need it's utilities.

The gettext utilities should be available or installable on all *nix based systems, as well as some sons/daugthers and parents (like BSDs and apple stuff).
If you are stuck on windows, your best bet may be [cygwin](http://www.cygwin.com/) (as always). There is also [MinGW](http://www.mingw.org/), a [sourceforge project](http://sourceforge.net/projects/gettext/), as well as [this site](http://franco-bez.4lima.de/index.php?option=com_content&view=article&id=55&Itemid=64&lang=en).
I have not tried any of the above currently beside my own linux box, but I believe that if would be no problem for a windows developer with decent skills to modify the script ;)

#### Known issues

* There is one big FAT issue currently: Internally all strings are contained in a single array. Meaning that you can not translate the same key in two different ways in the same page call.<br />I believe that our application is "small enough", so this wont really be an issue.<br />There is a solution deep down in my head, but it hasn't been translated to code yet ;) WIP
* Pluralization is supported but not implemented yet. WIP
* JavaScript translations and pluralizations are supported but not implemented yet. WIP
* Performance... This will be the last time that I mention that I'm lazy but... to avoid ugly escaping/unescaping of quotes, I simply base64 encode and decode the string and md5 encode the key which is, I admit that, very very time consuming W-I-P...

#### Refs

* https://github.com/elkuku/g11n - The experimental language handler oO

Demo: If you want to see this in action there is a staging instance which is currently running with full debug enabled [here](https://tracker-joomla54.rhcloud.com/) (link will change)

----
P.S.: I tried to keep this post short but seems like I failed miserably... sorry for the long post and thanks if you made it that far =;)
P.P.S.: <del>I just realized, that this PR also contains commits from #123, so it should be clearer after that</del> is merged ;)