many lines of text inside an Object Box can mess up the GUI viewport
* check when the user types "Enter" in an object or message box, and
  grown the svg viewBox if necessary
This should close the corresponding bug

many lines of text inside an Object Box can mess up the GUI viewport
This should fix cases that come from pasting an enormous amount of text
inside the box

increase timeout for rendering the "save before quit" dialog, as it sometimes doesn't get centered in the viewport (presumably because the zoomlevel hasn't finished resetting yet)

a few stray bug fixes and issues found with jslint. It suggests a larger, incremental refactoring to make the code more maintainable.