Changes to rely on fog-core

This references `fog-core` and removes the files it now contains.

Gemfile

@@ -5,4 +5,5 @@ group :development, :test do
   gem 'coveralls', :require => false
 end
 
+gem "fog-core", :github => "fog/fog-core", :branch => "master"
 gemspec

fog.gemspec

@@ -41,6 +41,7 @@ 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('builder')
   s.add_dependency('excon', '~>0.31.0')
   s.add_dependency('formatador', '~>0.2.0')

lib/fog.rb

@@ -3,6 +3,19 @@
 __LIB_DIR__ = File.expand_path(File.dirname(__FILE__))
 $LOAD_PATH.unshift __LIB_DIR__ unless $LOAD_PATH.include?(__LIB_DIR__)
 
+# Use core
+require 'fog/core'
+
+# Previously treated as "core"
+# data exchange specific (to be extracted and used on a per provider basis)
+require 'fog/xml'
+require 'fog/json'
+require 'fog/core/parser'
+
+# deprecation wrappers (XML wrapped version)
+require 'fog/core/deprecated/connection'
+require 'fog/core/deprecated_connection_accessors'
+
 # any one of these can be required separately.
 # they all depend on fog/core for shared functionality.
 require 'fog/atmos'