Moved "MoveTo…" functionality into Add-Worksheet and gave it copy worksheet functionality
Added create new file functionality to Open-ExcelPackage - requires a -create switch so previous "Open for read if it exists" behaviour is kept.
Fixed Conditional formatting so background pattern is "None" not "Solid" by default.
Tidied comments and help in Merge and Compare
Added Join Worksheet
Added Extra parameters, sanity check and help to New-PivotTableDefinition
