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/helper.rb

@@ -12,9 +12,9 @@ module Ruby
     def compile_main(input)
       RubyCompiler.compile(as_main(input))
     end
-    def compile_main_vool(input)
+    def compile_main_sol(input)
       xcompiler = RubyX::RubyXCompiler.new(RubyX.default_test_options)
-      xcompiler.ruby_to_vool(as_main(input))
+      xcompiler.ruby_to_sol(as_main(input))
     end
 
     def assert_raises_muted &block
@@ -28,25 +28,25 @@ module Ruby
     include RubyTests
     def setup
       super
-      @vool = compile( "class Tryout < Base; #{attr_def};end" ).to_vool
+      @sol = compile( "class Tryout < Base; #{attr_def};end" ).to_sol
     end
     def getter
-      @vool.body.statements.first
+      @sol.body.statements.first
     end
     def setter
-      @vool.body.statements.last
+      @sol.body.statements.last
     end
     def test_class
-      assert_equal Vool::ClassExpression , @vool.class
+      assert_equal Sol::ClassExpression , @sol.class
     end
     def test_body
-      assert_equal Vool::Statements , @vool.body.class
+      assert_equal Sol::Statements , @sol.body.class
     end
     def test_getter
-      assert_equal Vool::MethodExpression , getter.class
+      assert_equal Sol::MethodExpression , getter.class
     end
     def test_getter_return
-      assert_equal Vool::ReturnStatement , getter.body.class
+      assert_equal Sol::ReturnStatement , getter.body.class
     end
     def test_getter_name
       assert_equal :page , getter.name