List installed packages
+npm.commands.ls(args, [silent,] callback)
+This command will print to stdout all the versions of packages that are +installed, as well as their dependencies, in a tree-structure. It will also +return that data using the callback.
+This command does not take any arguments, but args must be defined.
+Beyond that, if any arguments are passed in, npm will politely warn that it
+does not take positional arguments, though you may set config flags
+like with any other command, such as global to list global packages.
It will print out extraneous, missing, and invalid packages.
+If the silent parameter is set to true, nothing will be output to the screen, +but the data will still be returned.
+Callback is provided an error if one occurred, the full data about which +packages are installed and which dependencies they will receive, and a +"lite" data object which just shows which versions are installed where. +Note that the full data object is a circular structure, so care must be +taken if it is serialized to JSON.
+Show extended information.
+Show parseable output instead of tree view.
+List packages in the global install prefix instead of in the current +project.
+Note, if parseable is set or long isn't set, then duplicates will be trimmed. +This means that if a submodule has the same dependency as a parent module, then the +dependency will only be output once.
+ +