Hello,
The very helpful png file showing the Moteino pinout lists PC0 as the pin for D2 and INT0. (lower left corner)
this page
http://lowpowerlab.com/moteino/#flash (http://lowpowerlab.com/moteino/#flash)
I think this is pin PD2 as PC0 is already in use as D14 (upper right).
You got it!
Thanks for pointing this out, this is now fixed!