This flag allows users on UNIX systems to set the tty for the program
being debugged by Delve. This is useful for debugging command line
applications which need access to their own TTY, and also for
controlling the output of the debugged programs so that IDEs may open a
dedicated terminal to show the output for the process.

* service: also search IPv6 connections when checking user

When checking if the user is allowed to connect to this Delve instance
also search IPv6 connections even though the local address is IPv4.

Fixes #1835

* cmd: add flag to disable same-user check

Fixes #1835

Before doing anything check that the version of Go is compatible with
the current version of Delve.
This will improve the error message in the case that  another change as
disruptive as Go1.11 dwarf compression, happens.

Adds a config file option to allow specifying a list of directories to
search in when looking for seperate external debug info files.

Fixes #1353

Change the linux verison of proc/native and proc/gdbserial (with
debugserver) so that they let the target process use the terminal when
delve is launched in headless mode.

Windows already worked, proc/gdbserial (with rr) already worked.
I couldn't find a way to make proc/gdbserial (with lldb-server) work.

No tests are added because I can't think of a way to test for
foregroundness of a process.

Fixes #65

* proc: Add `wd` to Launch

This change adds the `wd` arg which specify working directory of the
program.

Fixes #295

* service/debugger: Add `Wd` field to debugger.Config

This change adds the `Wd` field which specify working directory of the
program launched by debugger.

Fixes #295

* service: Add `Wd` to service.Config

This change adds the `Wd` field which specify working directory of the
program debugger will launch.

Fixes #295

* cmd/dlv: Add `Wd` flag

This change adds `Wd` flag which specify working directory of the
program which launched by debugger.

Fixes #295

* only set the Linux working directory if it is set,
stub out param in darwin and windows

* set working directory for Windows
https://godoc.org/golang.org/x/sys/windows#CreateProcess
https://msdn.microsoft.com/en-us/library/windows/desktop/ms682425(v=vs.85).aspx

* Windows workingDir must be an *uint16

* attempt to chdir on darwin via @yuntan

* proc/exec_darwin.c: fix working directory for darwin

* Add tests to check if working directory works.
* Fix darwin implementation of fork/exec, which paniced if
  child fork returned.

* cmd, service: rename Wd to WorkingDir

This version preserves the order of requests, allows the
client to switch between API versions and introduces a
way to send notifications to the client (see TODO item at:
proc/proc_linux.go:325).

Fixes #523, #571