initial prototype implementation for issue #856
Merge branch 'develop' of github.com:trhura/erpnext
changed stock_frozen_upto to stock_frozen_upto_days, and added validation for it in stock ledger
tabify modifications, minor coding style/message updates
import add_date, removed timedelta import
label/message update in error reporting
Merge branch 'develop' of https://github.com/webnotes/erpnext into develop
fixed typo add_date -> add_days
fix bug by coercing `stock_frozen_upto_days` value to int
initial tests for freeze stock functionality
Merge branch 'develop' of https://github.com/webnotes/erpnext into develop
added StockFreezeError, and uncomment stock_auth_role check
Merge pull request #1361 from trhura/develop

Pull request for issue #856