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/parfait/test_sol_method.rb

@@ -1,13 +1,13 @@
 require_relative "helper"
 
-module Vool
-  class TestVoolMethod < MiniTest::Test
-    include VoolCompile
+module Sol
+  class TestSolMethod < MiniTest::Test
+    include SolCompile
 
     def setup
       Parfait.boot!(Parfait.default_test_options)
       ruby_tree = Ruby::RubyCompiler.compile( as_main("a = 5") )
-      @clazz = ruby_tree.to_vool
+      @clazz = ruby_tree.to_sol
     end
     def method
       @clazz.body.first
@@ -22,7 +22,7 @@ module Vool
     end
     def test_method
       clazz =  @clazz.to_parfait
-      assert_equal Parfait::VoolMethod , clazz.get_instance_method(:main).class
+      assert_equal Parfait::SolMethod , clazz.get_instance_method(:main).class
     end
     def test_type_method
       clazz =  @clazz.to_parfait

test/parfait/test_space.rb

@@ -7,7 +7,7 @@ module Parfait
       [:Behaviour ,:BinaryCode,:Block,:CacheEntry,:Callable,:CallableMethod,:Class,
         :DataObject,:Data4,:Data8,:Data16,:Data32,:Dictionary,:Factory, :Integer,:FalseClass,
         :List,:Message, :SingletonClass,:NilClass,:Object,:ReturnAddress,
-        :Space,:TrueClass,:Type,:VoolMethod,:Word]
+        :Space,:TrueClass,:Type,:SolMethod,:Word]
     end
 
     def test_space_length