Fix issue with local data store not being properly cleared for VM destruction

lib/vagrant/vm.rb

@@ -89,9 +89,9 @@ module Vagrant
       env.local_data[:active] ||= {}
 
       if value && value.uuid
-        env.local_data[:active][name.to_sym] = value.uuid
+        env.local_data[:active][name.to_s] = value.uuid
       else
-        env.local_data[:active].delete(name.to_sym)
+        env.local_data[:active].delete(name.to_s)
       end
 
       # Commit the local data so that the next time vagrant is initialized,

test/vagrant/data_store_test.rb

@@ -26,6 +26,13 @@ class DataStoreTest < Test::Unit::TestCase
     assert_equal @initial_data["foo"], @instance[:foo]
   end
 
+  should "read the data by stringifying keys" do
+    @instance[:bar] = { "baz" => "yay" }
+    @instance.commit
+    @instance = @klass.new(@db_file)
+    assert_equal "yay", @instance[:bar]["baz"]
+  end
+
   should "write the data, but not save it right away" do
     @instance[:foo] = "changed"
     assert_equal "changed", @instance[:foo]

test/vagrant/vm_test.rb

@@ -57,13 +57,13 @@ class VMTest < Test::Unit::TestCase
       should "add the VM to the active list" do
         assert @env.local_data.empty?
         @vm.vm = @raw_vm
-        assert_equal @raw_vm.uuid, @env.local_data[:active][@vm.name.to_sym]
+        assert_equal @raw_vm.uuid, @env.local_data[:active][@vm.name.to_s]
       end
 
       should "remove the VM from the active list if nil is given" do
-        @env.local_data[:active] = { @vm.name.to_sym => "foo" }
+        @env.local_data[:active] = { @vm.name.to_s => "foo" }
 
-        assert @env.local_data[:active].has_key?(@vm.name.to_sym) # sanity
+        assert @env.local_data[:active].has_key?(@vm.name.to_s) # sanity
         @vm.vm = nil
 
         # This becomes empty because vm= will commit the local data which