Improve navigatibility with toolbar

[frcroth]

As a user, who uses the tool for the first time, I want to be able to navigate the program seamlessly. I want a toolbar similar to the toolbar of the Squeak World and other programs, in order to find my way through all the functionality.

Acceptance criteria:

• There is a toolbar in SquidWord
• The toolbar has less categories than the current amount of buttons
• Current functionality is reflected in the toolbar

Estimated effort: 5

[frcroth]

Possible categorization:

• File
  • New
  • Save in Image as
  • Save in Image
  • Save as File
  • Open from Image
  • Import from File
• Document
  • Structures
  • Undo
  • Redo
  • Info
  • Inspect Document
• Help