Fixing some wrong declaring of $dbh, and replace with correct query handler.
Fixing some wrong declaring of $dbh in change_avatar.php, and replace with correct query handler.
Fixing some wrong declaring of $dbh in change_password.php, and replace with correct query handler.
Fixing some wrong declaring of $dbh in change_username.php, and replace with correct query handler.
Fixing some wrong declaring of $dbh in edit_cv.php, and replace with correct query handler.
Fixing some wrong declaring of $dbh in familytree.php, and replace with correct query handler.
Fixing some wrong declaring of $dbh in feedback.php, and replace with correct query handler.
Fixing some wrong declaring of $dbh in filter.php, and replace with correct query handler.
Fixing some wrong declaring of $dbh in fix_media_comments.php, and replace with correct query handler.
Delete unnecessary files: fix_companies.php, fix_locations.php, and fix_mobiles.