release/dataTable.es6.js
function ForceFillColumnWidths(allColumns, expectedWidth, startIdx){
  var contentWidth = 0,
      columnsToResize = startIdx > -1 ?
        allColumns.slice(startIdx, allColumns.length).filter((c) => { return c.canAutoResize }) :
        allColumns.filter((c) => { return c.canAutoResize });

  allColumns.forEach((c) => {
    if(!c.canAutoResize){
      contentWidth += c.width;
    } else {
      contentWidth += (c.$$oldWidth || c.width);
    }
  });

  var remainingWidth = expectedWidth - contentWidth,
      additionWidthPerColumn = remainingWidth / columnsToResize.length,
      exceedsWindow = contentWidth > expectedWidth;

  columnsToResize.forEach((column) => {
    if(exceedsWindow){
      column.width = column.$$oldWidth || column.width;
    } else {
      if(!column.$$oldWidth){
        column.$$oldWidth = column.width;
      }

      var newSize = column.$$oldWidth + additionWidthPerColumn;
      if(column.minWith && newSize < column.minWidth){
        column.width = column.minWidth;
      } else if(column.maxWidth && newSize > column.maxWidth){
        column.width = column.maxWidth;
      } else {
        column.width = newSize;
      }
    }
  });
}
function ForceFillColumnWidths(allColumns, expectedWidth, startIdx){
  var contentWidth = 0,
      columnsToResize = startIdx > -1 ?
        allColumns.slice(startIdx, allColumns.length).filter((c) => { return c.canAutoResize }) :
        allColumns.filter((c) => { return c.canAutoResize });

  allColumns.forEach((c) => {
    if(!c.canAutoResize){
      contentWidth += c.width;
    } else {
      contentWidth += (c.$$oldWidth || c.width);
    }
  });

  var remainingWidth = expectedWidth - contentWidth,
      additionWidthPerColumn = remainingWidth / columnsToResize.length,
      exceedsWindow = contentWidth > expectedWidth;

  columnsToResize.forEach((column) => {
    if(exceedsWindow){
      column.width = column.$$oldWidth || column.width;
    } else {
      if(!column.$$oldWidth){
        column.$$oldWidth = column.width;
      }

      var newSize = column.$$oldWidth + additionWidthPerColumn;
      if(column.minWith && newSize < column.minWidth){
        column.width = column.minWidth;
      } else if(column.maxWidth && newSize > column.maxWidth){
        column.width = column.maxWidth;
      } else {
        column.width = newSize;
      }
    }
  });
}
Forces the width of the columns to
distribute equally but overflowing when nesc.

Rules:

- If combined withs are less than the total width of the grid,
proporation the widths given the min / max / noraml widths to fill the width.

- If the combined widths, exceed the total width of the grid,
use the standard widths.

- If a column is resized, it should always use that width

- The proporational widths should never fall below min size if specified.

- If the grid starts off small but then becomes greater than the size ( + / - )
the width should use the orginial width; not the newly proporatied widths.

@param {array} allColumns
@param {int} expectedWidth