[Proposal] Internationalizing XWiki Applications

[Vincent Massol]

Hi,

Here's my proposal for internationalizing XWiki apps. The idea is to  
propose several solutions for XWiki apps writers:

* Use case 1: I have lots of text on my page
   - solution: use XWiki's mechanism for translating page by creating  
several editions of the page in the different languages

* Use case 2: I want translation resources for my application only  
and I'd like to share resources between pages
   - solution: use:  $msg("mykey",  
"MySpace.MyTranslationDocForThisApplication")
   - MySpace.MyTranslationDocForThisApplication is a standard  
document to which a XWiki.PropertiesClass object is attached
   - It'll search first in that doc's PropertiesClass and if not  
found in XWiki's registered document bundles and if not there in  
XWiki's static resource bundle files

* Use case 3: I want translation resources only for a given page
   - solution: use:  $msg("mykey", $doc)
   - You'll need to have attached a PropertieClass object to the page  
where $msg is used
   - It'll search first in that object and if not found in XWiki's  
registered document bundles and if not there in XWiki's static  
resource bundle files

* Use case 4: I want to have a global translation resources for all  
my apps in the wiki
   - solution: use:  $msg("mykey")
   - You'll need to have created ad registered resource bundle  
documents in the Wiki preferences
   - It'll search first in XWiki's registered document bundles and if  
not there in XWiki's static resource bundle files

Implementation details:

* Add XWikiMessageTool.get(String, String) API
* Add XWiki.PropertiesClass class in XE in the Administration  
Application + a class sheet for presenting the properties nicely

WDYT?

Thanks
-Vincent