Admin: Some checking for existing usernames.
Merged master fixed conflict
Merge branch 'nkmittal4994-teacher'
Admin: Edit teacher and student structure
edit teacher option
edit teacher option
edit teacher option
edit teacher option
edit teacher option
edit teacher option
edit teacher option
edit teacher option
edit teacher option
Fixed some login issues
edit teacher option
edit teacher option
Update teacher.php
Update students_layout.php
Update teacher_m.php
Update teacher_m.php