Convert Dynamic Headers into multiple rows

[robert-bor]

Two aspects:

• headers must be copyable to fields of a row
• variable columns must be joinable with static columns

Commodity, Location, 01-14, 02-14 Corn, NL, 1, 2 Corn, BE, 3, 4

Result: Corn, NL, 01-14, 1 Corn, NL, 02-14, 2 Corn, BE, 01-14, 3 Corn, BE, 02-14, 4