Add elisp and js support for disconnecting from the server.

The motivating use case is a nodejs server that wants to shut down but
blocks until the debugger disconnects.  This situation arises often
when a developer is using a tool like nodemon that automatically
restarts the server on every source file change.

indium-client.el

@@ -149,6 +149,14 @@ Once the client is connected, run the hook `indium-client-connected-hook'."
                       (lambda (&rest _)
 			(run-hooks 'indium-client-connected-hook))))
 
+(defun indium-client-disconnect (&optional callback)
+  "Disconnect from the runtime, but do not stop the indium process.
+
+When non-nil, evaluate CALLBACK with the result."
+  (indium-client-send `((type . "connection")
+                        (payload . ((action . "disconnect"))))
+                      callback))
+
 (defun indium-client-evaluate (expression &optional frame callback)
   "Evaluate EXPRESSION in the context of FRAME.
 

server/README.md

@@ -116,6 +116,18 @@ Array of configurations.
 
 No payload.
 
+#### disconnect
+
+*Request payload:*
+
+| Key    | Type or value  | Description |
+|:-------|:---------------|:------------|
+| action | `"disconnect"` | Action type |
+
+*Successful response payload:*
+
+No payload.
+
 #### close
 
 *Request payload:*

server/server/connection.js

@@ -5,6 +5,8 @@ const connection = (data = {}, { success, error, stop }) => {
 	switch(data.action) {
 		case "connect":
 			return connect(data, { success, error });
+		case "disconnect":
+			return disconnect({ success, error });
 		case "close":
 			return stop();
 		default:
@@ -61,4 +63,13 @@ const connectToNode = async (options = {}, { success, error }) => {
 	success("Connected to Node!");
 };
 
+const disconnect = async ({ success, error }) => {
+	try {
+		await adapter.disconnect();
+	} catch(e) {
+		return error(e.message);
+	}
+	success("Disconnected");
+};
+
 module.exports = connection;