- added some descriptive comments in Active event example
- removed all Active Events unit tests from sample project, since they're
  now redundant due to that better tests exists in unit test project
- tons of more unit tests, especially for expressions
- slightly changed logic of "pf.set" keyword, such that it can set multiple
  values, but only to value and name expressions, which if there are multiple
  values, name or value is set to "code version" of result expression matches
  ** rethink ** this to make sure it is correct ...