I've gone ahead and addressed all of the significant issues raised here:

* Squeezer is no longer an extension
* Expanding problematically large outputs prompts the user for confirmation
* "copy" and "view" moved to a right-click context menu
* use IDLE's TextView for viewing squeezed outputs
  * I added the ability to set the text wrapping
* default minimum # lines for auto-squeezing increased to 50

I've also updated all of the tests accordingly and added a few.

There a several tweaks to consider, including those mentioned in my previous message, plus colors and key bindings.

This is now ready for another review!