Bump version 3.1.4
Merge branch '3.1.x'
Merge remote-tracking branch 'origin/hotfix'
Merge branch 'master' into origin/hotfix
Move delta 5 into delta 4 and remove sql mode in 6

The database versions between 3.0 to 3.1 are all 4. So delta_5 should be
merged into 4
Fix the failed test and update version in sample data
Fix missing formLoaded parameter in event editing

formLoaded parameter is added to ensure the page is loaded before user
can click submit.