Implement Row Grey Out using foreground rather than background colour
CHANGED: greyRows() fn to use cell rather than row changes
ADDED: setCellClass() fn to switch row's cell class
CSS: Add cell grey out style, remove row grey out style, refactored
CHANGED: StyleDefn now has tdClassGreyOut as entry, not trClassGreyOut
Merge pull request #14 from Hiblet/GreyOut02

Implement Row Grey Out using foreground rather than background colour