Add Credit note allocation
Merge pull request #40 from BlueChilli/master

Pull in BlueChilli's capability to apply CreditNotes to Invoices
contact api update for balances, payment terms and batch payments
Merge pull request #42 from nodero/xero_contacts_api_updates

contact api update for balances, payment terms and batch payments
Bump the version number
Merge remote-tracking branch 'upstream/master'