Implements extensible mechanism to specify which commands accept
prefixes (goroutine, frame, on) instead of hardcoding them in
a switch.
Implements #240
The 'source' command reads the file specified as argument and executes
it as a list of delve commands.
Additionally a flag '--init' can be passed to delve specifying a file
containing a list of commands to execute on startup.
Issue #96
Refactor to introduce client/server separation, including a typed
client API and a HTTP REST server implementation.
Refactor the terminal to be an API consumer.