Replace existing datepickers with material2 datepicker

[joachimprinzbach]

From @marcosteybe on June 28, 2016 8:55

Currently there are at least 2 different styles of date pickers integrated into the app. See for example date picker for offer creation vs date picker for camp creation (in camp workflow)!

Copied from original issue: joachimprinzbach/ng2-camp#34

[joachimprinzbach]

From @ailedt on June 30, 2016 16:12

• use material2 datepicker once ready and replace existing datepickers in app. make sure dates are prefilled when editing offerRequests or offers in application..
  https://github.com/angular/material2