Returns the content width for a given column width.
Original signature is '- (CGFloat)columnContentWidthForColumnWidth:(CGFloat)columnWidth'
Available in Mac OS X v10.3 and later.


- columnWidth (CGFloat)
- The width of the column. This width is the entire scrolling text view.

The width of the content for the column. This is the width of the matrix in the column.

- Available in Monobjc Bridge: 10.6 (For Mac OS X 10.6 and later), 10.5 (For Mac OS X 10.5 and later)