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.

src/kits/interface/CheckBox.cpp

@@ -452,7 +452,7 @@ BSize
 BCheckBox::MaxSize()
 {
 	return BLayoutUtils::ComposeSize(ExplicitMaxSize(),
-		BSize(B_SIZE_UNLIMITED, _ValidatePreferredSize().height));
+		_ValidatePreferredSize());
 }
 
 
@@ -464,6 +464,14 @@ BCheckBox::PreferredSize()
 }
 
 
+BAlignment
+BCheckBox::LayoutAlignment()
+{
+	return BLayoutUtils::ComposeAlignment(ExplicitAlignment(),
+		BAlignment(B_ALIGN_LEFT, B_ALIGN_VERTICAL_UNSET));
+}
+
+
 // #pragma mark -