Basic support for NSAttributedStrings and removed iOS6 warnings

Added a simple, new method (below) to add support for NSAttributedStrings. Also added conditionals to remove iOS6 warnings from using UITextAlignmentCenter and UILineBreakModeWordWrap.

+ (PopoverView *)showPopoverAtPoint:(CGPoint)point inView:(UIView *)view withTitle:(NSString *)title withAttributedStringArray:(NSArray *)stringArray delegate:(id<PopoverViewDelegate>)delegate;