Adding submodule git://github.com/dotphiles/dotphiles as vendor/dotphiles
Adding submodule git://github.com/milkbikis/powerline-bash as vendor/powerline-bash
Substantive update to package/plugin integration.

1.  Rewrote the hzsh plugin system to be able to load plugins defined by
    installed packages.
2.  Changed the package :install, :update, and :uninstall tasks to call
    a wrapper method (#__install__, #__update__, and #__uninstall__)
    instead of calling the defined plugin method directly. This allows
    all plugins to implement pre and post validation and action hooks.
    (Uninstall does not define a #post_uninstall_validate hook.)
3.  #__uninstall__ calls #uninstall only if it is defined (making it a
    hook), and then will remove the target tree if it still exists. This
    is because all uninstalls should just remove the target tree unless
    they require more precision as with packages like package/hub.rb
    which has a target of package/hub/src, but installs binaries into
    package/hub.
4.  Changed package:update:all to only update already installed
    packages.
5.  Added package:list as a synonym for package:known (or package).
6.  Cleaned up formatting of package:*:all and package:install:defaults
    descriptions.
7.  Reorganized the package code so that packages are now under
    halostatue/package/definitions/.
8.  Reorganized the package code so that the package definition
    generator is a separate class file and that most of the code is
    common to all generators now.
9.  Reorganied the package code so that the helper modules are now
    called package types and they contain the generator template extras.
10. Modified the package type modules (Git, Hg) to use the new function
    definition rules to prevent hooks like #pre_update_task from being
    called twice.
11. Added a VirtualEnv package type.
12. Extended the package definition code to be able to define hzsh
    plugins for installed plugins (see #1). Package method tasks call
    #update_plugin after calling the package wrapper method and before
    calling #update_package_list.
13. Cleaned up formatting of file:* descriptions.
14. `hub` is now a package. Removed the vendor:update:hub task.
15. Added an 'httpie' package.
16. Cleaned up the previously-manually-defined package plugins in favour
    of plugins supported by #1 generated by #12.