Fixed rendering of null values as '---' with new sheqel sign
Fixed saving of item.parent - moved it from SheetItem.save() to the sheet parser
Set self.parent.period_end to self.container_object.period_end if template is same as parent
Removed pip mirrors and pip simple.crate.io index
Added alias for spin.js.
Merge branch 'develop' of https://github.com/hasadna/omuni-budget into feature/volo-to-bower