- BFD/DFS/Dijkstra compile test is done with skeleton::GraphSkeleton graph
and skeleton::ReadMap.
- 'skeleton::' is explicitely written instead of 'using namespace ...'
in graph_test.cc
- Output messages of type "makeRep(3)..." in unionfind_test.cc have been
changed in order not to confuse compiler output parsers.

p min 3 3

n 3 s

n 2 t

a 3 1 20 20

a 1 2 20 10

a 1 2 20 0