Set param -name automatically (docker run)

``-name`` ist needed for linking containers, i.e. see http://docs.docker.io/en/latest/use/working_with_links_names/#working-with-links-names
added as ``args << ``
core: Vagrant.installer_embedded_dir
core: load system plugins if they are installed
core: add tests fornew systems path for plugin manager
core: plugin manager marks system gems as system
commands/plugin: list notes system gems
core: better error if attempting to uninstall system plugin
core: safer dup checks for synced folders
Merge pull request #3051 from mattes/patch-1

provisioners/docker: set param -name automatically (docker run)
UPdate CHANGELOG
provisioners/docker: setting to not auto assign name
provisioners/docker: actual auto assign name logic
core: set default server URL
website/www: add hyper-v preview image
website/www: Hyper-V blog post
core: use default color by default (not white)
core: rescue version conflicts when setting up Bundler
core: packaging works again
guests/redhat: force remove files so it works with pty