Merge pull request #214 from inthause/documents

[NEW] Add Rest "actions" namespace
[NEW] JSON and Object properties now uses decoded values in their getters and setters.
[NEW] Tax edition form.
[FIX] Some fixes in collections.
Merge pull request #215 from intportg/dev

JSON, Tax, Collections...
Fixed cascaded forms.
Added Tag saving into the database: we can now attach Tags to Documents and retrieve them.
Added possibility to set the "style" and "class" attributes on the <preview/> tag in <rbs-document-list/> directive.
Merge pull request #216 from fredericbonjour/Admin

Added Tag saving into the database.
Update build script
Merge pull request #217 from franckstauffer/plugins

Update build script
Add Event on DbProvider.

Add Predicates/Exists class.
Add Predicate HasTag