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/game_playertrade/playertrade.lua

@@ -1,7 +1,7 @@
 tradeWindow = nil
 
 function init()
-  g_ui.importStyle('tradewindow.otui')
+  g_ui.importStyle('tradewindow')
 
   connect(g_game, { onOwnTrade = onGameOwnTrade,
                     onCounterTrade = onGameCounterTrade,

modules/game_playertrade/playertrade.otmod

@@ -4,6 +4,6 @@ Module
   author: edubart
   website: www.otclient.info
   sandboxed: true
-  scripts: [ playertrade.lua ]
+  scripts: [ playertrade ]
   @onLoad: init()
   @onUnload: terminate()