server binary install usability improvements

[lnihlen]

Early testing has uncovered a bunch of usability improvements that could help increase the odds of a successful install:

• [x] instructions should remind folks to restart the interpreter after installing the quark
• [x] improvements to error messages on scinsynth server exit detection
• [x] instructions should be boiled down to numbered items in a list
• [x] might be worth considering some kind of automatic setup code in the server code