Correct EventPattern in HL

[mkommend]

As recommended the standard pattern for firing events should be implemented as follows [0]:

public event EventHandler MyEvent;
protected virtual void OnMyEvent()
{
    EventHandler handler = MyEvent;
    if (handler != null) handler(this, EventArgs.Empty);
} 

After discussions with swagner this should be corrected in the trunk, especially reading the event handler into a local variable. The EventArgs as a method parameter are not essential, because this could be another source of error (e.g. allocating new EventArgs instead of using EventArgs.Empty) and are therefore created in the method.

[0] ​http://blogs.msdn.com/cburrows/archive/2010/03/30/events-get-a-little-overhaul-in-c-4-afterward-effective-events.aspx

[swagner]

Firing of events has been corrected in the context of the cloning refactoring (see ticket #922).