Merge logic from VariationHelper to VariationExpert and Builder

[drdeteck]

A 2010 project introduced VariationExpert VariationBuilder logics while, in the same time, a 2013 project introduced a VariationHelper. The Helper has been moved to the Globalization.Variation namespace, but the merge of the methods must be done. The only 2 methods that seems to be used are SyncList and SyncWeb in the PowerShell dll.