Add shortest path first sequential search algorithm for unweighted graphs.

Signed-off-by: Michael Lippautz <michael.lippautz@gmail.com>
Fix compilation of thread id balancer.

Signed-off-by: Michael Lippautz <michael.lippautz@gmail.com>
Add parent attribute to vertex structure.

Signed-off-by: Michael Lippautz <michael.lippautz@gmail.com>