support platform-dependent 'shell' and 'shellArguments' options

[NiklasRosenstein]

I use the same configuration for Atom on Windows and Mac OS, so being able to customize the shell and shellArguments option for both platforms is crucial to me. This pull request allows me to configure the terminal like this

core:
  windows:
    shellArguments: "/k C:\\Users\\niklas\\bin\\cmdinit.bat"

However, I do not know the Atom API well enough to know how to modify the visual Configuration Page of the package to reflect this change. Any hints are appreciated.

[NiklasRosenstein]

If this gets merged, eventually it would make sense to use * to match any platform besides the ones already configured instead of specifying shell and shellArguments on the same level. What I mean is currently you can do this

core:
  shell: "/bin/bash"
  windows:
    shell: "cmd.exe"

Whereas it would probably make more sense to use

core:
  "*":
    shell: "/bin/bash"
  windows:
    shell: "cmd.exe"

[NiklasRosenstein]

Confirmed that it's working fine on Windows.

[the-j0k3r]

@ivankravets this is unlikely to go anywhere. Close?

[the-j0k3r]

@NiklasRosenstein rebase on master and push

[the-j0k3r]

@NiklasRosenstein if you ever want to enhance this package see https://github.com/bus-stop/terminus now written in JavaScript

[the-j0k3r]

closing as no result after this long