Shortest path from src node to src node is now computed correctly

The shortest path's weight is d-dimensional null vector
Method to print a Path with more detail

Prints all intermediate Paths
MSP: Formatting
Revert "Introduce class "aligned_data" to provide portable way for aligend memory allocations."

This reverts commit f738683990ef30a43d74868a4e58af46f9f222bd.

Conflicts:
	test/prefix_sum/PrefixSumTest.h
Test: Include <chrono>

This fixes a compilation error introduced by revision 473 "Switch to
std::chrono.".
MSP: Make node ID assignment deterministic
MSP: Add an adapter for the Paixao & Santos graphs

The graph database is publicly available from:
http://www.mat.uc.pt/~zeluis/INVESTIG/MSPP/mspp.htm
MSP: Don't leak the generated graph
benchmarks now controlled via args
REBASEME: tmp fix while waiting for Martins work