Use fog-json

This extracts the JSON encoding/decoding wrappers around MultiJson to a
separate gem.

Providers can use this shared behaviour in their standalone modules as
we work through things.

fog.gemspec

@@ -42,10 +42,11 @@ Gem::Specification.new do |s|
   ## List your runtime dependencies here. Runtime dependencies are those
   ## that are needed for an end user to actually USE your code.
   s.add_dependency("fog-core")
+  s.add_dependency("fog-json")
+
   s.add_dependency('builder')
   s.add_dependency('excon', '~>0.31.0')
   s.add_dependency('formatador', '~>0.2.0')
-  s.add_dependency('multi_json', '~>1.0')
   s.add_dependency('mime-types')
   s.add_dependency('net-scp', '~>1.1')
   s.add_dependency('net-ssh', '>=2.1.3')

lib/fog/json.rb

@@ -1,47 +0,0 @@
-require "multi_json"
-
-module Fog
-
-  # @note Extracting JSON components out of core is a work in progress.
-  #
-  # The {JSON} module includes functionality that is common between APIs using
-  # JSON to send and receive data.
-  #
-  # The intent is to provide common code for provider APIs using JSON but not
-  # require it for those using XML.
-  #
-  module JSON
-    class EncodeError < Fog::Errors::Error; end
-    class DecodeError < Fog::Errors::Error; end
-
-    def self.sanitize(data)
-      case data
-      when Array
-        data.map {|datum| sanitize(datum)}
-      when Hash
-        for key, value in data
-          data[key] = sanitize(value)
-        end
-      when ::Time
-        data.strftime("%Y-%m-%dT%H:%M:%SZ")
-      else
-        data
-      end
-    end
-
-    # Do the MultiJson introspection at this level so we can define our encode/decode methods and perform
-    # the introspection only once rather than once per call.
-
-    def self.encode(obj)
-      MultiJson.encode(obj)
-    rescue => err
-      raise EncodeError.slurp(err)
-    end
-
-    def self.decode(obj)
-      MultiJson.decode(obj)
-    rescue => err
-      raise DecodeError.slurp(err)
-    end
-  end
-end