Minor - format code.
Fix get message sender - refs #7338
Merge pull request #450 from AngelFQC/7338

Fix get message sender - refs #7338
Merge branch '1.9.x' of ssh://github.com/chamilo/chamilo-lms into chamilo19
Format code + adding api_get_cidreq
Fixing preview iframe see BT#9161
Fixing iframe
Fixing iframe + improving queries.
Fixing URL
Fixing forum link delete.
Minor - format code.
Fixing delete attachment condition.
Adding cidreq + format code.
Undo change 2990cd053a305397d3b76af7fd2f82cdb696add9
Adding intval, see #7440
Adding intval see #7440
Minor - format code.
Adding hosting_limit_active_courses setting see BT#9175
Blocking course edition see BT#9175
Minor, format code + fixing PHP warnings.