Rework the password dialog

It's now used as a general purpose "account edit dialog". It'll be used
for entering usernames, passwords, or both.

gui/dialogs/EditAccountDialog.h

@@ -0,0 +1,56 @@
+/* Copyright 2013 MultiMC Contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <QDialog>
+
+namespace Ui {
+class EditAccountDialog;
+}
+
+class EditAccountDialog : public QDialog
+{
+Q_OBJECT
+
+public:
+	explicit EditAccountDialog(const QString& text="", QWidget *parent = 0, int flags=UsernameField | PasswordField);
+	~EditAccountDialog();
+
+	/*!
+	 * Gets the text entered in the dialog's username field.
+	 */
+	QString username() const;
+
+	/*!
+	 * Gets the text entered in the dialog's password field.
+	 */
+	QString password() const;
+
+	enum Flags
+	{
+		NoFlags=0,
+
+		//! Specifies that the dialog should have a username field.
+		UsernameField,
+
+		//! Specifies that the dialog should have a password field.
+		PasswordField,
+	};
+
+private:
+	Ui::EditAccountDialog *ui;
+};
+