Consistent event naming and arguments

[jkruse]

With the number of API's growing, being consistent with event names and their arguments is increasingly important. Event names should be short and concise, only using longer names when needed to disambiguate. OnFullscreenChange and OnFullscreenError are good examples of bad naming (should be OnChange and OnError).

Similarly, events that recur across API's, like OnError should always receive the same arguments (error name and error message in this case). If different arguments are needed, the event should be differently named.