Implement and test WebConsole::REPL::IRB#send_interrupt
Suppress ^C to the STDOUT on interruptions
Raise ::IRB::Abort only in the fiber's thread
Make the interrupt test more strict
No need for the custom fibers anymore
No need for the stream capturing too
Drop the adapters concept
Turn WebConsole::REPL into a process master
Adjust the model to the new REPLs

Not the best idea, but let it be for now.