This commit makes the hdb server send a reverse-request to the client
and ask it to run @hdb proxy --port ...@ in a Terminal connected to the
client. From this Terminal, the user can send input to the debuggee and
read its output without additional debugger messages. It is just as if
the program was running in that terminal, but it is just a shim program
which forwards input/output to the debugger that is running the debuggee

Fixes #44

Depends on patch to dap which allows runInTerminal response to be
received

This makes it less likely for one to accidentally crash the DAP server
by clicking on play twice (the second time falling on top of the pause
button)