added the observer, passing the expanded list of data, not only the time...

... and *args

```
PulseMeter::Observer::Extended.observe_method(Class, :method, sensor) do |p|
  # p is a Hash with keys:
  # :self -- the ref to the object with call :method (or class if use observe_class_method)
  # :delta -- execution time in milliseconds
  # :result -- :method return value
  # :args -- list of :method arguments
  # :exception -- exception object or nil
end
```