remove 'overwrite' comment
Solves Bug#7179

Solves problem editing password when username=email
Format code, fixing PHP warnings, removing old comments.
Merge branch '1.9.x' of ssh://github.com/chamilo/chamilo-lms into chamilo19
Fix issue with student download of own work - refs BT#8151
Merge branch '1.9.x' of ssh://github.com/chamilo/chamilo-lms into chamilo19
Merge pull request #323 from AngelFQC/7179

Solves Bug#7179
Merge branch '1.9.x' of ssh://github.com/chamilo/chamilo-lms into chamilo19
Should fix #7179
Minor - format code, PHP warnings.
Fixing - PHP warnings, format code.
Fixing PHP warnings.
Using session course order instead of the name see BT#8316
Adding user session duration see BT#8317
Merge pull request #316 from emarguin/fix_comment_doc

remove 'overwrite' comment
Minor - white spaces, format code.
Merge branch '1.9.x' of ssh://github.com/chamilo/chamilo-lms into chamilo19
Minor - add documentation and error condition to session duration-related functions - refs #8317
Add better messaging and a few error cases to sessions duration by user edition screen - refs #8317
Add better messaging (show user and session names) to sessions duration by user edition screen - refs #8317