Added transaction lists to invoice details page fixes #623
fixing tests
fixing invoices tests
Merge pull request #646 from tarunc/invoice-transaction

Added transaction lists to invoice details page fixes #623
added print view
added support for print stylesheet; stylesheet for printing invoices; customer address string
fixed hidden print styles; fixes #624
hide transaction table
use a little more less variables
added span mixin to print css
added span mixin to print css