Change some header icons
icons changed:
- profile settings: user icon to cog
- admin area: cogs to wrench
Based on https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/719#note_1289290
Do not update/delete: Banner broadcast message test data
Do not update/delete: Notification broadcast message test data
icons changed:
Based on https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/719#note_1289290