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/ruby/test_send_statement1.rb

@@ -1,69 +1,69 @@
 require_relative "helper"
 
 module Ruby
-  class TestSendNoArgVool < MiniTest::Test
+  class TestSendNoArgSol < MiniTest::Test
     include RubyTests
     def setup
-      @lst = compile( "foo").to_vool
+      @lst = compile( "foo").to_sol
     end
     def test_simple_class
-      assert_equal Vool::SendStatement , @lst.class
+      assert_equal Sol::SendStatement , @lst.class
     end
     def test_simple_name
       assert_equal :foo , @lst.name
     end
     def test_simple_receiver
-      assert_equal Vool::SelfExpression , @lst.receiver.class
+      assert_equal Sol::SelfExpression , @lst.receiver.class
     end
     def test_simple_args
       assert_equal [] , @lst.arguments
     end
   end
-  class TestSendSimpleArgVool < MiniTest::Test
+  class TestSendSimpleArgSol < MiniTest::Test
     include RubyTests
     def setup
-      @lst = compile( "bar(1)").to_vool
+      @lst = compile( "bar(1)").to_sol
     end
     def test_class
-      assert_equal Vool::SendStatement , @lst.class
+      assert_equal Sol::SendStatement , @lst.class
     end
     def test_name
       assert_equal :bar , @lst.name
     end
     def test_receiver
-      assert_equal Vool::SelfExpression , @lst.receiver.class
+      assert_equal Sol::SelfExpression , @lst.receiver.class
     end
     def test_args
-      assert_equal Vool::IntegerConstant ,  @lst.arguments.first.class
+      assert_equal Sol::IntegerConstant ,  @lst.arguments.first.class
     end
   end
-  class TestSendSuperVool < MiniTest::Test
+  class TestSendSuperSol < MiniTest::Test
     include RubyTests
     def test_super0
-      lst = compile( "super").to_vool
-      assert_equal Vool::SuperStatement , lst.class
+      lst = compile( "super").to_sol
+      assert_equal Sol::SuperStatement , lst.class
     end
     def test_super0_receiver
-      lst = compile( "super").to_vool
-      assert_equal Vool::SelfExpression , lst.receiver.class
+      lst = compile( "super").to_sol
+      assert_equal Sol::SelfExpression , lst.receiver.class
     end
   end
-  class TestSendSuperArgsVool < MiniTest::Test
+  class TestSendSuperArgsSol < MiniTest::Test
     include RubyTests
     def setup
-      @lst = compile( "super(1)").to_vool
+      @lst = compile( "super(1)").to_sol
     end
     def test_super_class
-      assert_equal Vool::SuperStatement , @lst.class
+      assert_equal Sol::SuperStatement , @lst.class
     end
     def test_super_receiver
-      assert_equal Vool::SelfExpression , @lst.receiver.class
+      assert_equal Sol::SelfExpression , @lst.receiver.class
     end
     def test_super_name
       assert_equal :super,  @lst.name
     end
   end
-  class TestSendReceiverTypeVool < MiniTest::Test
+  class TestSendReceiverTypeSol < MiniTest::Test
     include RubyTests
 
     def setup
@@ -71,12 +71,12 @@ module Ruby
     end
 
     def test_int_receiver
-      sent = compile( "5.div4").to_vool
+      sent = compile( "5.div4").to_sol
       assert_equal Parfait::Type , sent.receiver.ct_type.class
       assert_equal "Integer_Type" , sent.receiver.ct_type.name
     end
     def test_string_receiver
-      sent = compile( "'5'.putstring").to_vool
+      sent = compile( "'5'.putstring").to_sol
       assert_equal Parfait::Type , sent.receiver.ct_type.class
       assert_equal "Word_Type" , sent.receiver.ct_type.name
     end
@@ -84,13 +84,13 @@ module Ruby
   class TestSendReceiver < MiniTest::Test
     include RubyTests
     def setup
-      @lst = compile( "call.once.more").to_vool
+      @lst = compile( "call.once.more").to_sol
     end
     def test_class
-      assert_equal Vool::Statements , @lst.class
+      assert_equal Sol::Statements , @lst.class
     end
     def test_one
-      assert_equal Vool::LocalAssignment , @lst.first.class
+      assert_equal Sol::LocalAssignment , @lst.first.class
     end
     def test_one_name
       assert @lst[0].name.to_s.start_with?("tmp_")
@@ -105,7 +105,7 @@ module Ruby
       assert_equal :once , @lst[1].value.name
     end
     def test_three_class
-      assert_equal Vool::SendStatement, @lst[2].class
+      assert_equal Sol::SendStatement, @lst[2].class
     end
     def test_three_name
       assert_equal :more , @lst[2].name