Fix the "getRowAt" method in TerraTableViewSkin so that the
variable row height case works the same as fixed height:
return -1 if the y value is beyond the end of the table
otherwise return the correct row.


git-svn-id: https://svn.apache.org/repos/asf/pivot/branches/2.0.x@1453906 13f79535-47bb-0310-9956-ffa450edef68