Windows resizing enhancements

[al-develop]

• add editing of windows size by using ctrl + mouse wheel, when the mouse hovers over the "windows size" area.
• add display of the current window size.
• add direct editing of window size through textboxes.

  allow only values between the min width/height and max width/height.
  --> always edit width and height together. The only way to change only width or only height should happen through the alt+h / alt+w +mouse wheel feature (see Can't resize the window #10 ). The reasoning behind this: adding more controls to always change width and height separately, will fill up too much space. The TextEditor must remain the main control.

• make it possible to resize the window even smaller. Adjust the controls accordingly to the window size.

  add a setting entry to restore only the size. The idea: if the user resizes the window to a degree where its too difficult to resize it back up, it's more convenient to restore only the size. Of course this could be achieved through the already existing "reset settings" entry, but it is more user-friendly to keep the other settings as they were.