WTemplate has two new nodes: {block} and {range}
Null variables are not saved anymore in WRequest
News: admin side upgraded / bug fixes
User app admin refreshed
Bug fix on WController : permissions were not parsed
News App : few cleansing
WRoute: the query keeps slashes at the extremity
DB cleansing

All tables have 4 fields: created_date, created_by, modified_date,
modified_by
News: Bug fix on category creation
WDatabase updates 4 default fields for UPDATE and INSERT requests

Also, added mail DB schema in installer/wity.sql
Fixes a configuration key mistake from last commit in SQL
WDate calculates elapsed time + added system lang files
Clean apps's lang files
Wording error in wdate lang
Merge remote-tracking branch 'origin/0.4' into news-wretriever

Conflicts:
	system/WCore/WMain.php
	system/WCore/WRequest.php
	system/WCore/WRoute.php