Large collections shouldn't print everything by default

[jackfirth]

Large collections cause problems when they're printed:

• They lock up DrRacket when printed at the REPL, making it unresponsive.
• Scribble docs that print large collections cause the doc page to balloon in size and become difficult to navigate
• Logged collections and collections printed by debuggers massively inflate message size and drown out all other information

To fix these issues, collections should limit how much they print. Contract error messages already do this and print a ... that is clickable in DrRacket, and clicking it reveals the rest of the message. Something similar should occur with Rebellion's collection types.