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

data/styles/30-inputboxes.otui

@@ -0,0 +1,30 @@
+InputBoxLabel < Label
+  fixed-size: true
+  text-align: left
+InputBoxLineEdit < TextEdit
+InputBoxTextEdit < MultilineTextEdit
+  text-wrap: true
+InputBoxSpinBox < SpinBox
+InputBoxCheckBox < CheckBox
+InputBoxComboBox < ComboBox
+InputBoxComboBoxPopupMenu < ComboBoxPopupMenu
+InputBoxComboBoxPopupMenuButton < ComboBoxPopupMenuButton
+InputBoxButton < Button
+  margin-left: 10
+  fixed-size: true
+
+InputBoxButtonsPanel < Panel
+  height: 20
+  margin-top: 4
+  focusable: false
+  layout:
+    type: horizontalBox
+    align-right: true
+
+InputBoxWindow < MainWindow
+  __class: UIInputBox
+  width: 260
+  layout:
+    type: verticalBox
+    fit-children: true
+    spacing: 2