Fix setting stickyfooter and header top and bottom not considering multi header/footer rows#133

msabljak wants to merge 2 commits intodiprokon:masterdiprokon/ng-table-virtual-scroll:masterfrom

msabljak:bugfix/multiple_sticky_rows_unsupportedmsabljak/ng-table-virtual-scroll:bugfix/multiple_sticky_rows_unsupportedCopy head branch name to clipboard