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_styles/styles.lua

@@ -0,0 +1,21 @@
+function init()
+  local styles = g_resources.listDirectoryFiles('/styles')
+  for _i,style in pairs(styles) do
+    if string.ends(style, '.otui') then
+        g_ui.importStyle('/styles/' .. style)
+    end
+  end
+
+  local fonts = g_resources.listDirectoryFiles('/fonts')
+  for _i,font in pairs(fonts) do
+    if string.ends(font, '.otfont') then
+      g_fonts.importFont('/fonts/' .. font)
+    end
+  end
+
+  -- TODO load particles
+end
+
+function terminate()
+end
+