Add date shortcuts to customize buttons (#1406)
Add date shortcuts to customize buttons (#1406)

SDFID-503

Each custom date field will have three customizable buttons providing
for each button the following parameters:
  - value: for example 2
  - term: for example 'days'
  - label: for example 'In two days'
petrjasek/superdesk-core,superdesk/superdesk-core,ioanpocol/superdesk-core,mdhaman/superdesk-core,superdesk/superdesk-core,ioanpocol/superdesk-core,mdhaman/superdesk-core,superdesk/superdesk-core,mdhaman/superdesk-core,petrjasek/superdesk-core,ioanpocol/superdesk-core,petrjasek/superdesk-core,superdesk/superdesk-core,petrjasek/superdesk-core