initial south migrations for stock models
Merge pull request #149 from dimagi/stock-models

initial south migrations for stock models
add stock_id to stock models and ota restore
sort stock block by stock-id when multiple stocks exist
fix query bug, update string representation of stocks to includ stock_id
Merge pull request #150 from dimagi/stock-id

add stock_id to stock models and ota restore
stock-id --> section-id
stock_id --> section_id
product --> entry
add stock admin
Merge pull request #152 from dimagi/ledger-spec-updates

Ledger spec updates
Merge branch 'commtrack' into staging