Create table model for tasks tab.
Create button panel for tasks tab.
Create tasks panel and insert it into TabbedPane.
Implement clearing tasks panel.
Implement CRUD in table model.
Implement filling tasks panel with data, when loading file.
Implement reading data from tasks panel, when saving file.
Implement task form dialog and display it, when new task button is pressed.
Use combo box instead of text field for task type in task form dialog.
Add newly created task in task form dialog to tasks panel.
Implement editing task in tasks panel.
Add selection listener to tasks table.
Implement deleting tasks in tasks panel.
Merge branch 'tasks-tab'