Interface Kit: Adjust max size and default alignment...

...on controls where it makes sense:
- BRadioButton and BCheckBox now return their preferred size as their
maximum.
- BRadioButton, BCheckBox and BTextControl now use left alignment by
default, as this is the most common use case for them.

headers/os/interface/CheckBox.h

@@ -17,9 +17,9 @@ public:
 									uint32 flags = B_WILL_DRAW | B_NAVIGABLE);
 								BCheckBox(const char* name, const char* label,
 									BMessage* message, uint32 flags
-										= B_WILL_DRAW | B_NAVIGABLE); 
+										= B_WILL_DRAW | B_NAVIGABLE);
 								BCheckBox(const char* label,
-									BMessage* message = NULL); 
+									BMessage* message = NULL);
 								BCheckBox(BMessage* archive);
 
 	virtual						~BCheckBox();
@@ -55,6 +55,7 @@ public:
 	virtual	BSize				MinSize();
 	virtual	BSize				MaxSize();
 	virtual	BSize				PreferredSize();
+	virtual	BAlignment			LayoutAlignment();
 
 	virtual	void				MakeFocus(bool focused = true);
 

headers/os/interface/RadioButton.h

@@ -61,7 +61,7 @@ public:
 	virtual	status_t			Perform(perform_code d, void* argument);
 
 	virtual	BSize				MaxSize();
-
+	virtual	BAlignment			LayoutAlignment();
 
 private:
 	friend	status_t			_init_interface_kit_();

headers/os/interface/TextControl.h

@@ -86,6 +86,7 @@ public:
 	virtual	BSize				MinSize();
 	virtual	BSize				MaxSize();
 	virtual	BSize				PreferredSize();
+	virtual	BAlignment			LayoutAlignment();
 
 			BLayoutItem*		CreateLabelLayoutItem();
 			BLayoutItem*		CreateTextViewLayoutItem();