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_class_def.rb

@@ -0,0 +1,42 @@
+require_relative "helper"
+
+module Sol
+  class TestClassDef < MiniTest::Test
+    include SlotMachine
+    include SolCompile
+
+    def class_main
+      <<-eos
+        class Space
+          def self.one_plus()
+            return 1 + 1
+          end
+          def main(arg)
+            return Space.one_plus
+          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_any
+      assert_equal SlotMachine::MessageSetup , @ins.class
+    end
+    def test_no_arg
+      assert_equal SlotMachine::ArgumentTransfer,  @ins.next(1).class
+      assert_equal 0,  @ins.next(1).arguments.length
+    end
+    def test_call_two
+      assert_equal SimpleCall,  @ins.next(2).class
+    end
+  end
+end