Add data_output interface
Add data_output interface

For slight abstraction and OO-ification of serialization.

avikivity/scylla,eklitzke/scylla,respu/scylla,acbellini/scylla,rluta/scylla,capturePointer/scylla,rentongzhang/scylla,tempbottle/scylla,wildinto/scylla,raphaelsc/scylla,aruanruan/scylla,dwdm/scylla,bowlofstew/scylla,gwicke/scylla,duarten/scylla,rluta/scylla,linearregression/scylla,wildinto/scylla,scylladb/scylla,eklitzke/scylla,senseb/scylla,phonkee/scylla,bowlofstew/scylla,acbellini/scylla,linearregression/scylla,linearregression/scylla,senseb/scylla,guiquanz/scylla,raphaelsc/scylla,asias/scylla,phonkee/scylla,scylladb/scylla,tempbottle/scylla,eklitzke/scylla,rentongzhang/scylla,wildinto/scylla,capturePointer/scylla,dwdm/scylla,raphaelsc/scylla,glommer/scylla,stamhe/scylla,kangkot/scylla,dwdm/scylla,avikivity/scylla,asias/scylla,victorbriz/scylla,rluta/scylla,kangkot/scylla,kangkot/scylla,asias/scylla,duarten/scylla,capturePointer/scylla,scylladb/scylla,tempbottle/scylla,duarten/scylla,acbellini/scylla,gwicke/scylla,gwicke/scylla,bowlofstew/scylla,avikivity/scylla,kjniemi/scylla,shaunstanislaus/scylla,victorbriz/scylla,aruanruan/scylla,phonkee/scylla,stamhe/scylla,guiquanz/scylla,justintung/scylla,shaunstanislaus/scylla,aruanruan/scylla,justintung/scylla,scylladb/scylla,glommer/scylla,rentongzhang/scylla,shaunstanislaus/scylla,glommer/scylla,respu/scylla,victorbriz/scylla,kjniemi/scylla,respu/scylla,stamhe/scylla,guiquanz/scylla,justintung/scylla,kjniemi/scylla,senseb/scylla