Application:
- Implement "Save" menu

Functionality:
- Context menu in symbol navigator
- Delete symbols before/after selected
- Shift all symbols on code line (change symbol codes)
- Specify starting conde (extends the shift)
- "Only numbers" range in the New dialog
- "Specify range" in the New dialog
- "Single frame", "only numbers" and "specify range" as radio buttons
- Undo/Redo
- Image import from a file
- Import from a text array