Enables array support for osx_defaults provider

It takes an array of objects and Shellwords escapes each entry

Signed-off-by: Jonathan Barnes <jonathan@codeword.net>
Allows the removal of default apps from the dock

No more photobooth, no more garageband sitting in the dock next to
RubyMine. This can be turned on/off via the configuration setting:
'dock_preferences'->'clear_apps'

Also allows for the dock size to be adjusted and makes orientation
adjustment optional via configuration setting

Signed-off-by: Jonathan Barnes <jonathan@pivotallabs.com>
Merge pull request #116 from codeword/dockPreferences

Allows the removal of default apps from the dock