Add BufferedNodeProcess to execute apm and nak.

On Windows the shebang string is not supported, so we haveto execute apm
and nak as scripts instead of as executables.

src/app/project.coffee

@@ -7,7 +7,7 @@ Buffer = require 'text-buffer'
 EditSession = require 'edit-session'
 EventEmitter = require 'event-emitter'
 Directory = require 'directory'
-BufferedProcess = require 'buffered-process'
+BufferedNodeProcess = require 'buffered-node-process'
 
 # Public: Represents a project that's opened in Atom.
 #
@@ -292,7 +292,7 @@ class Project
     ignoredNames = config.get('core.ignoredNames') ? []
     args.unshift('--ignore', ignoredNames.join(',')) if ignoredNames.length > 0
     args.unshift('--addVCSIgnores') if config.get('core.excludeVcsIgnoredPaths')
-    new BufferedProcess({command, args, stdout, stderr, exit})
+    new BufferedNodeProcess({command, args, stdout, stderr, exit})
     deferred
 
   ### Internal ###

src/packages/settings-view/lib/package-manager.coffee

@@ -1,4 +1,4 @@
-BufferedProcess = require 'buffered-process'
+BufferedNodeProcess = require 'buffered-node-process'
 roaster = require 'roaster'
 async = require 'async'
 
@@ -41,7 +41,7 @@ getAvailable = (callback) ->
     else
       callback(new Error("apm failed with code: #{code}"))
 
-  new BufferedProcess({command, args, stdout, exit})
+  new BufferedNodeProcess({command, args, stdout, exit})
 
 install = ({name, version}, callback) ->
   activateOnSuccess = !atom.isPackageDisabled(name)
@@ -59,7 +59,7 @@ install = ({name, version}, callback) ->
       actom.activatePackage(name) if activateOnFailure
       callback(new Error("Installing '#{name}' failed."))
 
-  new BufferedProcess({command, args, exit})
+  new BufferedNodeProcess({command, args, exit})
 
 uninstall = ({name}, callback) ->
   atom.deactivatePackage(name) if atom.isPackageActive(name)
@@ -73,6 +73,6 @@ uninstall = ({name}, callback) ->
     else
       callback(new Error("Uninstalling '#{name}' failed."))
 
-  new BufferedProcess({command, args, exit})
+  new BufferedNodeProcess({command, args, exit})
 
 module.exports = {renderMarkdownInMetadata, install, uninstall, getAvailable}

src/stdlib/buffered-node-process.coffee

@@ -0,0 +1,21 @@
+BufferedProcess = require 'buffered-process'
+path = require 'path'
+
+# Like BufferedProcess, but accepts a node script instead of an executable,
+# on Unix which allows running scripts and executables, this seems unnecessary,
+# but on Windows we have to separate scripts from executables since it doesn't
+# support shebang strings.
+module.exports =
+class BufferedNodeProcess extends BufferedProcess
+  constructor: ({command, args, options, stdout, stderr, exit}) ->
+    args = ['--atom-child_process-fork', command].concat(args)
+    node =
+      if process.platform is 'darwin'
+        # On OS X we use the helper process to run script, because it doesn't
+        # create an icon on the Dock.
+        path.resolve(process.resourcesPath, '..', 'Frameworks',
+                     'Atom Helper.app', 'Contents', 'MacOS', 'Atom Helper')
+      else
+        process.execPath
+
+    super({command: node, args, options, stdout, stderr, exit})