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/call_statement.rb

@@ -5,8 +5,8 @@ module Ruby
   #
   # A CallStatement has a name, receiver and arguments
   #
-  # Using the "vool_brother" we can create the right Vool class for it.
-  # Arguments in vool must be simple, so any complex expressions get
+  # Using the "sol_brother" we can create the right Sol class for it.
+  # Arguments in sol must be simple, so any complex expressions get
   # hoisted and assigned to temporary variables.
   #
   class CallStatement < Statement
@@ -18,17 +18,17 @@ module Ruby
     end
 
     # we "normalize" or flatten any complex argument expressions into a list
-    def to_vool
-      statements = Vool::Statements.new([])
+    def to_sol
+      statements = Sol::Statements.new([])
       receiver = normalize_arg(@receiver , statements)
       arguments = []
       @arguments.each_with_index do |arg , index |
         arguments << normalize_arg(arg , statements)
       end
       if statements.empty?
-        return vool_brother.new(@name, receiver , arguments)
+        return sol_brother.new(@name, receiver , arguments)
       else
-        statements << vool_brother.new(@name, receiver , arguments)
+        statements << sol_brother.new(@name, receiver , arguments)
         return statements
       end
     end
@@ -38,17 +38,17 @@ module Ruby
     # the effect is of walking the call tree now,
     # rather than using a stack to do that at runtime
     def normalize_arg(arg , statements)
-      vool_arg = arg.to_vool
-      return vool_arg if vool_arg.is_a?(Vool::Expression)
-      if( vool_arg.is_a?(Vool::Statements))
-        while(vool_arg.length > 1)
-          statements << vool_arg.shift
+      sol_arg = arg.to_sol
+      return sol_arg if sol_arg.is_a?(Sol::Expression)
+      if( sol_arg.is_a?(Sol::Statements))
+        while(sol_arg.length > 1)
+          statements << sol_arg.shift
         end
-        vool_arg = vool_arg.shift
+        sol_arg = sol_arg.shift
       end
-      assign = Vool::LocalAssignment.new( "tmp_#{arg.object_id}".to_sym, vool_arg)
+      assign = Sol::LocalAssignment.new( "tmp_#{arg.object_id}".to_sym, sol_arg)
       statements << assign
-      return Vool::LocalVariable.new(assign.name)
+      return Sol::LocalVariable.new(assign.name)
     end
 
   end