[hotfix] Supplier read permission for Purchase User

[Fix] Issue #448

[Fix] Issue #448 2
minor fix in sales invoice test records
[fix] issue 448 final
Merge branch 'develop' of https://github.com/frappe/erpnext into fix-issue-448
[fix] issue 448 final 1
Merge branch 'develop' of https://github.com/frappe/erpnext into fix-issue-448
Merge pull request #2108 from neilLasrado/fix-issue-448

[Fix] Issue #448