Respect XDG_CONFIG_HOME and XDG_CONFIG_DIRS.
https://specifications.freedesktop.org/basedir-spec/basedir-spec-latest.html#variables

Fixes #1048, closes #1061

If file is not present before checking for writing, remove it after check.
Add test to check for writeability in default location

Fixes #1314

Fixes weird failure that happens only on Windows:

    cannot use syscall.Stdin (type syscall.Handle) as type int in
    argument to terminal.GetState

I would guess `syscall.Stdin` is of different type on Windows and that
this might be a Go bug.

After the last howeyc/gopass update, hitting Enter after password input
makes the next printed line appear indented to the position of the
password prompt. I'm not sure what causes this, but as a workaround,
skip the howeyc/gopass dependency altogether and interface directly with
crypto/ssh/terminal.

Fixes #1262

See https://groups.google.com/forum/#!topic/golang-nuts/kTVAbtee9UA

howeyc/gopass@e7699d3d9eedadb8fafead56654e6459b57fe4cd

Sometimes when hub is cross-compiled, `user.Current()` won't work on
certain systems. Use an alternative way of obtaining the user's home
directory.

Now `ci-status` consumes the new combined statuses API endpoint designed
for when multiple contexts report statuses independently.

The verbose output is now colorized and is in format where each line is:

    ✔︎<Tab>[CONTEXT]<Tab>[URL]

Otherwise, it was re-read from file every time CurrentConfig() was accessed.

Fixes #463 and #948

Introduce a `console` package which encapsulates logic of printing out
to console. This provides flexibility of discarding output in tests.
It also allows us to unify format of printing to console (if we want to).

This fixes #801.

This is to fix Windows related home dir issue https://github.com/github/hub/issues/772

Reference: https://github.com/github/hub/issues/769

This is to follow implementation in https://github.com/github/hub/pull/738

`configService` can save and load `Config` using a strategy of `configEncoder` and `configDecoder`. This pave the path for swapping out `tomlConfigEncoder` and `tomlConfigDecoder` with `yamlConfigEncoder` and `yamlConfigDecoder`.

`Configs` also has been renamed to `Config`.

Defaults to HTTPS, but can be used to configure Enterprise instances
which are only accessible over HTTP.

This'll make sure we propagate error to the caller where we can reformat
the error message within the context.

This fixes `features/authentication.feature:85`

See comment https://github.com/github/hub/pull/515#discussion_r10915319