Issue770 modify the SGMAppController Upgrade Permission
alterred:
  - only the 'sgm' user would be able to do the upgrades
  - the other fawkes would be able to do the upgrades only when they run
the program with argument "--enableDatabaseUpgrade"
modify spaces with tabs
alter the unintended changes
- rename the argument
- remove the checking of the other usernames
refine the codes
Altered:
 - localize the const definitions
altered: change the naming style of const variables
Merge master branch to solve conflicts
Merge pull request #775 from acquaman/Issue770

Pull Request for Issue770: SGMAppController Upgrade Permissions

Tested on my machine. Appears to be working.