massive options.js cleanup. It is now only responsible for the options framework, but does not host

any option. They are now saved in the modules where the corresponding features are defined or in vim.js
if they are general options. Expect the same code rework for commands and mappings.

content/muttator.js

@@ -34,6 +34,7 @@ vimperator.config = {
     /*** optional options, there are checked for existance and a fallback provided  ***/
     features: ["mail", "hints"],
 	get mainWidget() { return GetThreadTree(); }, // focusContent() focuses this widget
+	mainWindowID: "messengerWindow", // used for :set titlestring
     dialogs: [],
     guioptions: { m: ["mail-toolbar-menubar2"], T: ["mail-bar2"], f: ["folderPaneBox", "folderpane_splitter"], F: ["folderPaneHeader"] }
 }