Adding options side menu support (Done)

Use:
 - (void)addButton:(UIButton *)button
toCellSide:(MCSwipeTableViewCellSide)side;

To add a menu button to one of the cell sides;

You can also set colors for the menu background color using the
properties leftMenuColor and rightMenuColor;

Remember that if a side has at least one button it will ignore the its
previous states.