Moves overridden property accessors from the OverriddenPropertyAccessors category to the main implementation so that the compiler doesn’t generate two setters for the corresponding properties. Since setters are not atomic, marks the corresponding properties as nonatomic. Fixes #6.
Column header resizing now cannot overlap. There's a minimum width on a column. Column headers now don't overlap their surrounding header cells. Header cell content now gets truncated if column width is too narrow.
Merge pull request #7 from brendand/master

Column header resizing now cannot overlap. There's a minimum width on a column
Keyboard navigation now scrolls the contentView when the selected cell moves off screen in order to keep the selected cell in view.
Merge pull request #8 from brendand/master

Keyboard navigation now scrolls the contentView
New Grid submenu with menu items to add/remove rows/columns and populate grid with the position labels.
Ignores drawing when the content view belongs to an empty grid.
When the grid is empty, sets the content view size to zero.
Fixes a bug where a column width might be set to zero in case -_widthForColumn: is sent with a column index out of order.
When reloading data, validates selected{Row,Column}Indexes and columnWidths because changes in the data source might render internal data invalid.
Changes the columnWidths dictionary so that the key is a boxed NSUInteger containing the column index instead of a string with format @“column%lu”.
Fixes a ‘row’ should be ‘column’ bug. :P
Reviews MBTableGrid so that all methods work when the grid empty. Still need to check drag-and-drop.