it's done
Merge remote-tracking branch 'upstream/master'
Merge branch 'master' of https://github.com/webnotes/erpnext

Conflicts:
	setup/doctype/backup_manager/backup_dropbox.py
	setup/doctype/backup_manager/backup_manager.py
Merge branch 'master' of https://github.com/webnotes/erpnext
no -ve balance accepted in sales and purchase invoice
Merge branch 'master' of https://github.com/webnotes/erpnext

Conflicts:
	controllers/buying_controller.py
merged backup dropbox file
merged backup manager python file
Merge pull request #312 from saurabh6790/master

updated accounts_controller.py, buying_controller.py, selling_controller.py