Remove confusing hint words from  git training tutorial

 Fix #981
Merge branch 'master' of https://github.com/openhatch/oh-mainline
Add edit links to main screen
Merge pull request #1361 from ehashman/issue1360

#1360 Add edit links to main screen
Merge pull request #263 from yaochen1994/master

Remove Confusing Hint Words from Tutorial  of Git Training Missions
Customize main bug set screen if user is/is not logged in
Merge pull request #1364 from ehashman/issue1360

Customize main bug set screen if user is/is not logged in
Add csrf_token to subscribe_to_bug_alert_do POST

Closes #1356