-i command line option should cause the REPL to be run

[josefsachsconning]

Keith Mason, in PR #10692, proposed making -I (uppercase) run the REPL.
The PR was closed by ihnorton, saying "It would be best to fix the existing options rather than add a new one."
and furthermore
"Right now -i just means "make isinteractive() return true" (see #6765). I think -i should mean "run-to-REPL" by default, like Python and bash. I don't believe this would conflict with IJulia or Gtk.jl/Julietta usage because they take over the event loop, but if it is a problem we could probably check whether isatty to decide."

[stevengj]

Seems reasonable to me.

[garrison]

+1

[tkelman]

This sounds way more useful to me than just changing the output of one function (what we currently use -i for).