Mention group and project names in flash messages upon create, update and delete.

Mention group and project names in flash messages upon create, update and delete. I also changed some wording inconsistency.

**Before**

![project_created](https://gitlab.com/axil/gitlab-ce/uploads/b91b92e46b08d6c566acee8d88fccff1/project_created.png)

**After**

![project_created_after](https://gitlab.com/axil/gitlab-ce/uploads/56db5125f2769386c43cf9e2f175a54d/project_created_after.png)

See merge request !1070