add some measurable benchmark / performance tests

[gullerya]

in order to get some picture i need to add some benchmark / performance tests scenarios, few ideas:

• adding element to tied DOM vs untied DOM (or an impact of element processing buy mutation observer, less precise)
  • element that is itself untied
  • element that is itself tied
• adding a simple tree to tied DOM vs untied DOM (or ... see above)
  • elements that are themselves untied
  • elements that are themselves tied
• performing multiple changes in model and measuring the speed of that
• ?