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_while_statement1.rb

@@ -1,19 +1,19 @@
 require_relative 'helper'
 
 module Ruby
-  class TestWhileStatementVool < MiniTest::Test
+  class TestWhileStatementSol < MiniTest::Test
     include RubyTests
     def setup
-      @lst = compile( "while(@arg) ; @arg = 1 ; end" ).to_vool
+      @lst = compile( "while(@arg) ; @arg = 1 ; end" ).to_sol
     end
     def test_class
-      assert_equal Vool::WhileStatement , @lst.class
+      assert_equal Sol::WhileStatement , @lst.class
     end
     def test_body_class
-      assert_equal Vool::IvarAssignment , @lst.body.class
+      assert_equal Sol::IvarAssignment , @lst.body.class
     end
     def test_condition_class
-      assert_equal Vool::InstanceVariable , @lst.condition.class
+      assert_equal Sol::InstanceVariable , @lst.condition.class
     end
     def test_no_hoist
       assert_nil @lst.hoisted
@@ -22,20 +22,20 @@ module Ruby
   class TestWhileStatementHoist < MiniTest::Test
     include RubyTests
     def setup
-      @lst = compile( "while(call(arg > 1)) ; arg = 1 ; end" ).to_vool
+      @lst = compile( "while(call(arg > 1)) ; arg = 1 ; end" ).to_sol
     end
     def test_class
-      assert_equal Vool::WhileStatement , @lst.class
-      assert_equal Vool::LocalAssignment , @lst.body.class
+      assert_equal Sol::WhileStatement , @lst.class
+      assert_equal Sol::LocalAssignment , @lst.body.class
     end
     def test_condition_class
-      assert_equal Vool::SendStatement , @lst.condition.class
+      assert_equal Sol::SendStatement , @lst.condition.class
     end
     def test_hoist
-      assert_equal Vool::Statements , @lst.hoisted.class
+      assert_equal Sol::Statements , @lst.hoisted.class
     end
     def test_hoist_is_assi
-      assert_equal Vool::LocalAssignment , @lst.hoisted.first.class
+      assert_equal Sol::LocalAssignment , @lst.hoisted.first.class
     end
   end
 end