Invoice API service's GetAllInvoices call changed to POST instead of GET.

Added Location field to product catalogInventory model (client-side) and Product View's Inventory Tracking section. Completes issue M-323, but the server's return after saving the updated product model with confirmed location field flushed out has it listed as 'NULL'.
Added support for sortBy and sortDirection to the GetAllInvoices calls in the invoices list controller.
Merge remote-tracking branch 'merchello/1.4.0-lists' into 1.4.0-lists
Modified sorting code in order list controller.
Merge remote-tracking branch 'merchello/1.4.0-lists' into 1.4.0-lists
Updated invoice services to use SearchInvoices instead of GetAllInvoices (need to modify some method names).
Merge pull request #809 from cssquirrel/1.4.0-lists

Invoice API service's GetAllInvoices call changed to POST instead of GET...