Make the DOM renderer stable

Also updated the list of features which are not supported now. Note
that this may be moved to an addon eventually, this can be part of a
major release rather than included in the comment.

Fixes #1671

typings/xterm.d.ts

@@ -144,19 +144,14 @@ declare module 'xterm' {
     macOptionClickForcesSelection?: boolean;
 
     /**
-     * (EXPERIMENTAL) The type of renderer to use, this allows using the
-     * fallback DOM renderer when canvas is too slow for the environment. The
-     * following features do not work when the DOM renderer is used:
+     * The type of renderer to use, this allows using the fallback DOM renderer
+     * when canvas is too slow for the environment. The following features do
+     * not work when the DOM renderer is used:
      *
-     * - Links
+     * - Link underlines
      * - Line height
      * - Letter spacing
      * - Cursor blink
-     * - Cursor style
-     *
-     * This option is marked as experiemental because it will eventually be
-     * moved to an addon. You can only set this option in the constructor (not
-     * setOption).
      */
     rendererType?: RendererType;