Fully deprecates the fontWeight attribute of SC.LabelView.
Fixes broken unit test for SC.ButtonView.
Removes meaningless property from SC.ButtonView.
Removes excess display property observers from SC.ButtonView (escapeHTML, needsEllipsis, tooltip) and SC.LabelView (escapeHTML, textAlign, fontWeight, needsEllipsis).  In the case of escapeHTML and needsEllipsis, these are used in the update rendering, but it seems highly unlikely that the value will need to change on the fly.  The docs have been updated to indicate how to support updating these values on the fly if necessary though.  In the case of the other properties, they no longer exist on the views.
Removes dependencies on deprecated textAlign property.
Also escapes the tool tip for SC.LabelView, which could also be a potential avenue of attack for XSS.