David Bomba 25514b43cf
Allow fine grained payments (#3110)
* Allow payment amounts to be partial per invoice paid

* edge case tests for payments

* Allow per invoice payment amounts and allow direct payments which simply credit a clients credit_balance

* Fixes
2019-12-01 22:23:24 +11:00
..
2019-11-16 14:12:29 +11:00