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/logical_statement.rb

@@ -7,7 +7,7 @@ module Ruby
   # ie: false && non_existant_method
   # will never call the non_existant_method , but instead evaluate to false
   #
-  # Vool has no concept of this, so the Statement is expanded into the if
+  # Sol has no concept of this, so the Statement is expanded into the if
   # that it really is
   class LogicalStatement < Statement
     attr_reader :name , :left , :right