Fix bugs in _examples/

[coloursofnoise]

• Add KeyBackspace keybind to dynamic.go to match input prompt ("Backspace: Delete View")
• Fix table alignment in table.go
  • Spacing issue caused by not accounting for empty chars being rendered as ' ' in View.draw:
    
  • Minor issue in example when trying to align columns properly:
    
  • (fixed):
    
• Disable visible cursor in mouse.go due to it being entirely mouse-controlled

[dankox]

If you could try and incorporate changes from #109 and see if that works for this, that would be good. It should target the table.go case where SetWritePos didn't work as expected.

[coloursofnoise]

Branch has been rebased onto master to incorporate changes from #109

[mjarkk]

LGTM