Fix OS X scrolling issue.  Closes #2078.
FIXED: CPSegementedControl with nib2cib crashes

When having a CPSegmentedControl within a a XIB files, nib2cib crashes with the following error:

```
'undefined' is not an object (evaluating 'self._themeStates[aSegment].without')
```

This pull request fixes the problem by making sure that the drawBezel method is called with a valid segment index when accessing the themeState.

Reduction: https://dl.dropboxusercontent.com/u/14629300/BugCPSegmentedControl.zip
New: Graphical CPDatePicker clicking on the arrows with key mask Command/Control/Alternate

Now when clicking on the arrows with the key mask Command/Control or Alternate change the date to 1 year or 10 years as in Cocoa.
Fixed: show placeholder string while editing empty CPTextField

Previously, selecting an empty text field hid the contentView, causing the placeholder string to dissapear. This fix leaves the contentView of the text field visible when the internal _stringValue is nil or empty.

Fixes #2049
Test: added manual test case to check for placeholder.

Refs #2049
New: Added CPPopoverDelegate protocole

Added CPPopopverDelegate protocole
New: Added CPSplitViewDelegate protocol

Added the CPSplitViewDelegate protocol.
Also, now, delegate methods are called as we are used to do it in Cappuccino
New: Added protocol CPAnimationDelegate

Added protocol CPAnimationDelegate.
Also, now, delegate methods are called as we are used to do it in Cappuccino

Test app in Tests/Manual/CPAnimationTest.
Fixed: CPAnimationDelegate protocol methods are required
Fixed: AppController of CPAnimationTest does not implement protocol CPAnimationDelegate
New: Added protocol CPSoundDelegate

Added protocol CPSoundDelegate.
Also, now, delegate methods are called as we are used to do it in Cappuccino
New: Added protocol CPImageDelegate.

Added protocol CPImageDelegate.
Also, now, delegate methods are called as we are used to do it in Cappuccino
Fixed: param of setDelegate: does not conform to protocol CPImageDelegate
New: Added protocol CPMenuDelegate

Added protocol CPMenuDelegate.
Also, now, delegate methods are called as we are used to do it in Cappuccino
New: Added CPComboDelegate protocol
New: Added CPRuleEditorDelegate protocol

Added CPRuleEditorDelegate protocol.
Also, now, delegate methods are called as we are used to do it in Cappuccino
New: Added CPTokenFieldDelegate protocol.

Added CPTokenFieldDelegate protocol.
Also, now, delegate methods are called as we are used to do it in Cappuccino
New: Added CPWindowDelegate protocol

Added CPWindowDelegate protocol
Also, now, delegate methods are called as we are used to do it in Cappuccino
Fixed: wonrd params for the method _sendDelegateWindowWillReturnUndoManager
New: Added CPControlTextEditingDelegate and CPTextFieldDelegate protocol

Added CPControlTextEditingDelegate and CPTextFieldDelegate protocol