Get terminals working

- Instead of a single listener per terminal that handles all events VS
  Code now has a single listener per event that handles that event for
  all terminals.
- Refactor Terminal to extend TerminalProcess to avoid duplicating
  methods. This required some modifications to TerminalProcess to access
  the pid and title and to set the ID.
- Remove our async change to shutdown. This was necessary to avoid
  disposing too early but shutdown already calls dispose so it turns out
  we didn't need to call it ourselves.
- Rename methods to match the command strings.
- Fix getting system shell (uses process.env).
- Use a single bufferer. Since it already supports buffering for
  multiple terminals there's no need to have one per terminal.
- Remove replay/reconnect logic. It's broken and unused so there doesn't
  seem much point in trying to refactor it to fit the changes right now.

While terminals work now there are still a lot of todos.

lib/vscode/src/vs/platform/terminal/node/terminalProcess.ts

@@ -45,14 +45,13 @@ const enum ShutdownConstants {
 }
 
 export class TerminalProcess extends Disposable implements ITerminalChildProcess {
-	readonly id = 0;
 	readonly shouldPersist = false;
 
 	private _exitCode: number | undefined;
 	private _exitMessage: string | undefined;
 	private _closeTimeout: any;
-	private _ptyProcess: pty.IPty | undefined;
-	private _currentTitle: string = '';
+	protected _ptyProcess: pty.IPty | undefined;
+	protected _currentTitle: string = '';
 	private _processStartupComplete: Promise<void> | undefined;
 	private _isDisposed: boolean = false;
 	private _windowsShellHelper: WindowsShellHelper | undefined;
@@ -82,6 +81,7 @@ export class TerminalProcess extends Disposable implements ITerminalChildProcess
 	public readonly onProcessShellTypeChanged = this._onProcessShellTypeChanged.event;
 
 	constructor(
+		public readonly id: number = 0,
 		private readonly _shellLaunchConfig: IShellLaunchConfig,
 		cwd: string,
 		cols: number,
@@ -293,9 +293,9 @@ export class TerminalProcess extends Disposable implements ITerminalChildProcess
 		this._onProcessTitleChanged.fire(this._currentTitle);
 	}
 
-	public async shutdown(immediate: boolean): Promise<void> {
+	public shutdown(immediate: boolean): void {
 		if (immediate) {
-			await this._kill();
+			this._kill();
 		} else {
 			if (!this._closeTimeout && !this._isDisposed) {
 				this._queueProcessExit();