First attempt at new batch printing interface

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extra : source : af2f6034fddae0187e0fbd00ee1b5445c6ca027a
Hopefully fixing synax error.

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extra : source : 6d1919890a6d1eb5cbe533701d075b8d42022a3c
Correcting call to fork().

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extra : source : f08be669f50d3c6b3603afcdb252579cd38327a7
Fixing syntax error and adding vendor invoices to batch printing

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extra : source : f32848f56ab9f39ccdc15573de11dc98bef19d8e
Adding pod to undocumented sub

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extra : source : e586ccd458737bf05e0e463f71182e3c6fa984cf
Fixing remaining errors

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extra : source : 415c45d42050dfb92055fca30db6c92be8592d20
adding missing semicolon

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extra : source : cc270780009e1ec8ed9e25937efa5d28d1ae01d5
Merge pull request #499 from einhverfr/master

New code, batch printing