Integrates only on the pixels needed and then works
on the rest of the pixels. To do this, I defined an
ordered linked list in sll.c that will put elements
in an ordered fashion. They pixels to be worked on
are inserted into the linked list based on their
distance from the center of the profile. When the
radius that integration is no longer necessary is
reached, this list is converted to an ordinary
simple linked list and the rest of the profile is filled
based on that, which is extremely simple and fast.

Fixes #1 .