Fix server not restarting itself on fatal error

This also cleans up the server startup in Proxy since most of the 
restarting logic is now handled by the Atom language client.

References #460

lib/Proxy.js

@@ -132,7 +132,6 @@ module.exports =
 
                     // this.closeServerConnection();
 
-                    this.phpServer = null;
                     reject();
                 });
             });
@@ -149,57 +148,18 @@ module.exports =
         }
 
         /**
-         * Spawns the PHP socket server process.
-         *
-         * @param {Number} port
-         *
          * @return {Promise}
         */
-        spawnPhpServerIfNecessary(port) {
-            if (this.phpServer) {
-                this.phpServerPromise = null;
+        async getSocketConnection() {
+            return new Promise(async(resolve) => {
+                const phpServer = await this.spawnPhpServer(this.port);
 
-                return new Promise((resolve, reject) => {
-                    return resolve(this.phpServer);
+                const client = net.createConnection({port: this.port}, () => {
+                    resolve([client, phpServer]);
                 });
 
-            } else if (this.phpServerPromise) {
-                return this.phpServerPromise;
-            }
-
-            const successHandler = phpServer => {
-                this.phpServer = phpServer;
-
-                return phpServer;
-            };
-
-            const failureHandler = () => {
-                return this.phpServerPromise = null;
-            };
-
-            this.phpServerPromise = this.spawnPhpServer(port).then(successHandler, failureHandler);
-
-            return this.phpServerPromise;
-        }
-
-        /**
-         * @return {Promise}
-        */
-        getSocketConnection() {
-            return new Promise((resolve, reject) => {
-                return this.spawnPhpServerIfNecessary(this.port).then(() => {
-                    if (this.client != null) {
-                        resolve(this.client);
-                        return;
-                    }
-
-                    this.client = net.createConnection({port: this.port}, () => {
-                        return resolve(this.client);
-                    });
-
-                    this.client.setNoDelay(true);
-                    this.client.on('error', this.onSocketError.bind(this));
-                });
+                client.setNoDelay(true);
+                client.on('error', this.onSocketError.bind(this));
             });
         }
 

lib/SerenataClient.js

@@ -61,9 +61,11 @@ class SerenataClient extends AutoLanguageClient
     }
 
     async startServerProcess() {
-        this.socket = await this.proxy.getSocketConnection();
+        let server;
 
-        return this.proxy.phpServer;
+        [this.socket, server] = await this.proxy.getSocketConnection();
+
+        return server;
     }
 
     preInitialization(connection) {