Refactor modules, closes #223

* All modules are sandboxed now
* All images,sounds,fonts,translations and styles were moved to "data" folder
* Reorganize image files folders
* Remove unmaintained modules: client_particles, client_shaders
* Implement new automatic way to load styles and fonts
* Add hide/show offline option in VipList
* Add invite/exclude to/from private channel in players menus
* Many other minor changes

modules/client_background/background.otmod

@@ -3,13 +3,8 @@ Module
   description: Handles the background of the login screen
   author: edubart
   website: www.otclient.info
-
-  dependencies:
-    - client_topmenu
-
-  @onLoad: |
-    dofile 'background'
-    Background.init()
-
-  @onUnload: |
-    Background.terminate()
+  sandboxed: true
+  scripts: [ background ]
+  dependencies: [ client_topmenu ]
+  @onLoad: init()
+  @onUnload: terminate()