Purchase Orders with spaces in the name cause problems with EDI processing

Evergreen: 2.7.2ish
PostgreSQL: 9.3 (n/a)
OpenSRF: 2.4ish (n/a)

When staff enter a purchase order with a space in the name, this causes a problem with picking line item ids out of the invoice and other messages returned by the vendor.

Bill Erickson and Kathy Lussier traced this to a regex used to parse these ID numbers. It currently includes a check for non-space characters.

Since staff are not prevented from entering spaces in PO names, and since vendors do not seem to have a problem with it, a proposed solution is to alter the regular expression.

See the forthcoming branch for that solution.