Removed the ability to create custom report levels

This feature relied on class level operations, which I'm not a fan of, and
wasn't really useful anyway.

Signed-off-by: Yorick Peterse <yorickpeterse@gmail.com>
Sort entries by file and line number.

Instead of sorting entries by file and error level they should be sorted by
file and line number.

Signed-off-by: Yorick Peterse <yorickpeterse@gmail.com>