New: Add the Contact Changing functionality to the database and backend

coscine/issues#1294 coscine/issues#789

added 4 commits

• 23729f7d...8a5e6086 - 3 commits from branch Product/789-userContactEmail
• 441250d5 - Merge remote-tracking branch 'remotes/origin/master' into Topic/1294-contactChangeFunctionality

Compare with previous version

resolved all threads

changed title from Topic/1294 contact change functionality to New: Add the Contact Changing functionality to the database and backend

mentioned in commit 2315bebc

merged