Rename Vool to Sol

Simple is really the descriptive name for the layer
Sure, it is "virtual" but that is not as important as the fact that it is simple (or simplified)
Also objct (based really) is better, since orientated implies it is a little like that, but only orientated, not really it. Sol only has objects, nothing else
Just cause i was renaming anyway

test/sol/class_send/test_send_class.rb

@@ -0,0 +1,62 @@
+require_relative "helper"
+
+module Sol
+  class TestSendClassSlotMachine < MiniTest::Test
+    include SolCompile
+
+    def class_main
+      <<-eos
+        class Space
+          def self.one_plus(one)
+            return 1 + 1
+          end
+        end
+        class Space
+          def main(arg)
+            return Space.one_plus(1)
+          end
+        end
+      eos
+    end
+
+    def setup
+      source = "class Integer < Data4;def +(other);X.int_operator(:+);end;end;" + class_main
+      ret = RubyX::RubyXCompiler.new(RubyX.default_test_options).ruby_to_slot(source)
+      @ins = ret.compilers.find_compiler_name(:main).slot_instructions.next
+    end
+
+    def test_array
+      check_array [MessageSetup,ArgumentTransfer,SimpleCall,SlotLoad,
+                    ReturnJump,Label, ReturnSequence , Label] , @ins
+    end
+
+    def test_class_compiles
+      assert_equal MessageSetup , @ins.class , @ins
+    end
+    def test_receiver
+      assert_equal SlotDefinition,  @ins.next.receiver.class
+      assert_equal Parfait::Class,  @ins.next.receiver.known_object.class
+      assert_equal :Object ,  @ins.next.receiver.known_object.name
+    end
+    def test_receiver_move
+      assert_equal SlotDefinition,  @ins.next.receiver.class
+    end
+    def test_receiver
+      assert_equal Parfait::Class,  @ins.next.receiver.known_object.class
+    end
+    def test_arg_one
+      assert_equal SlotLoad,  @ins.next(1).arguments[0].class
+    end
+    def test_receiver_move_class
+      assert_equal ArgumentTransfer,  @ins.next(1).class
+    end
+    def test_call_is
+      assert_equal SimpleCall,  @ins.next(2).class
+      assert_equal Parfait::CallableMethod,  @ins.next(2).method.class
+      assert_equal :one_plus,  @ins.next(2).method.name
+    end
+    def test_call_has_right_receiver
+      assert_equal "Space.Single_Type",  @ins.next(2).method.self_type.name
+    end
+  end
+end