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

lib/ruby/assignment.rb

@@ -6,11 +6,11 @@ module Ruby
       @name , @value = name , value
     end
 
-    def to_vool()
+    def to_sol()
       raise "not named left #{name.class}" unless name.is_a?(Symbol)
       case value
       when Variable , Constant
-        return self.vool_brother.new(name,@value.to_vool)
+        return self.sol_brother.new(name,@value.to_sol)
       when SendStatement , YieldStatement , RubyBlockStatement
         return normalize_send
       else
@@ -18,12 +18,12 @@ module Ruby
       end
     end
 
-    # sends may have complex args that get hoisted in vool:ing them
+    # sends may have complex args that get hoisted in sol:ing them
     # in which case we have to assign the simplified, otherwise the
     # plain send
     def normalize_send
-      statements = value.to_vool
-      return assignment( statements ) if statements.is_a?(Vool::CallStatement)
+      statements = value.to_sol
+      return assignment( statements ) if statements.is_a?(Sol::CallStatement)
       # send has hoisted assigns, so we make an assign out of the "pure" send
       statements << assignment(statements.statements.pop)
       statements
@@ -32,7 +32,7 @@ module Ruby
     # create same type assignment with the value (a send)
     def assignment(value)
       value ||= @value
-      self.vool_brother.new(name,value)
+      self.sol_brother.new(name,value)
     end
 
     def to_s(depth = 0)